30+ Common English Noun Roots with Examples and Definitions

Here are 30 common English noun roots with illustrative examples and definitions, along with 5 words for each root:

1. Act - 'actor' (a person who performs in plays or movies), 'action' (something done or performed), 'react' (to respond or behave in a certain way), 'enact' (to make into law), 'activate' (to make something active or operational)

2. Art - 'artist' (a person who creates artworks), 'artwork' (a creative expression or visual representation), 'artisan' (a skilled craftsperson), 'artifact' (an object made by humans), 'artful' (skillful or clever)

3. Bio - 'biology' (the study of living organisms), 'biodegradable' (capable of being decomposed by natural processes), 'biosphere' (the regions of the Earth occupied by living organisms), 'biotechnology' (the application of biological principles to technology), 'biometric' (relating to the measurement of biological characteristics)

4. Chron - 'chronology' (the arrangement of events in the order of their occurrence), 'chronic' (long-lasting or persistent), 'synchronize' (to cause to occur at the same time), 'chronometer' (a precise timekeeping device), 'anachronism' (something out of its proper time)

5. Geo - 'geography' (the study of the physical features of the Earth), 'geology' (the study of the Earth's structure and composition), 'geophysics' (the study of the Earth's physical properties), 'geothermal' (relating to heat within the Earth), 'geocentric' (having the Earth as the center)

6. Graph - 'graphology' (the study of handwriting and its interpretation), 'graphic' (relating to visual art or representation), 'autograph' (a person's own signature), 'epigraph' (an inscription at the beginning of a book), 'histogram' (a diagram representing frequency distributions)

7. Hydro - 'hydrology' (the study of water and its properties), 'hydroelectric' (relating to the generation of electricity using water power), 'dehydrate' (to remove water from something), 'hydrophobic' (repelling water), 'hydroponics' (the cultivation of plants in water)

8. Log - 'logic' (the study of valid reasoning and inference), 'dialogue' (a conversation between two or more people), 'catalog' (a list or record of items), 'analog' (relating to or using continuous physical quantities), 'prologue' (an introductory part of a book or play)

9. Opt - 'optical' (relating to sight or vision), 'optimize' (to make the best or most efficient use of something), 'optician' (a person who specializes in fitting eyeglasses), 'optometrist' (a person who examines eyes), 'optional' (not compulsory)

10. Phon - 'phonetics' (the study of speech sounds), 'telephone' (a device used for communication over long distances), 'symphony' (a musical composition for a full orchestra), 'phonograph' (a device for recording and reproducing sound), 'microphone' (a device for converting sound into electrical signals)

11. Photo - 'photography' (the art or practice of taking and processing photographs), 'photograph' (a picture taken by a camera), 'photosynthesis' (the process by which plants convert light into energy), 'photovoltaic' (relating to the conversion of light into electricity), 'photogenic' (attractive or suitable for photography)

12. Psych - 'psychology' (the study of the mind and behavior), 'psychiatrist' (a medical doctor specializing in mental health), 'psychoanalysis' (a method of treating mental disorders), 'psychosomatic' (relating to the interaction of the mind and body), 'psychopath' (a person with a personality disorder)

13. Scope - 'microscope' (an instrument used for viewing small objects), 'telescope' (an optical instrument used for viewing distant objects), 'periscope' (an optical instrument used for viewing objects above eye level), 'scope' (the range or extent of something), 'broadscope' (a wide-ranging view)

14. Tech - 'technology' (the application of scientific knowledge for practical purposes), 'technician' (a person skilled in a specific technical field), 'technical' (relating to a particular subject or occupation), 'technocrat' (a person who advocates the use of technology), 'technological' (relating to technology)

15. Tele - 'television' (a device for receiving and displaying broadcasted images and sound), 'telecommunication' (the transmission of information over a distance), 'teleport' (to transport instantly from one location to another), 'telegraph' (a device for sending messages over long distances), 'telemetry' (the transmission of data over long distances)

16. Therm - 'thermometer' (a device used for measuring temperature), 'thermal' (relating to heat or temperature), 'thermodynamics' (the study of energy conversion), 'thermos' (a container that keeps things hot or cold), 'thermostat' (a device that regulates temperature)

17. Astro - 'astronaut' (a person trained for space travel), 'astrology' (the study of celestial bodies and their influence on human affairs), 'astronomy' (the study of celestial objects and the universe), 'asteroid' (a small rocky body orbiting the Sun), 'astrophysics' (the study of the physical properties of celestial objects)

18. Bio - 'biography' (an account of someone's life written by someone else), 'biopsy' (the removal of tissue for examination), 'biochemical' (relating to the chemical processes in living organisms), 'biohazard' (a biological substance that poses a risk to health), 'bioethics' (the study of ethical issues related to biology and medicine)

19. Cardio - 'cardiovascular' (relating to the heart and blood vessels), 'cardiologist' (a doctor specializing in heart-related conditions), 'cardiogram' (a recording of the heart's electrical activity), 'cardiology' (the study of the heart and its diseases), 'cardiopulmonary' (relating to the heart and lungs)

20. Neuro - 'neuroscience' (the study of the nervous system and its functions), 'neurologist' (a doctor specializing in disorders of the nervous system), 'neurosis' (a mental or emotional disorder), 'neuron' (a nerve cell), 'neurotransmitter' (a chemical that transmits nerve impulses)

21. Philo - 'philosophy' (the study of fundamental questions about existence, knowledge, values, and reason), 'philanthropy' (the desire to promote the welfare of others), 'philosopher' (a person who seeks wisdom and knowledge), 'philology' (the study of languages), 'bibliophile' (a lover of books)

22. Anthropo - 'anthropology' (the study of human societies, cultures, and development), 'anthropologist' (a person who studies human societies and cultures), 'anthropomorphic' (attributing human characteristics to non-human entities), 'anthropometry' (the measurement of human body dimensions), 'anthropogenesis' (the origin and development of humans)

23. Demi - 'demigod' (a mythological being who is half human and half god), 'demiglace' (a rich sauce made by reducing stock), 'demimonde' (a group of people on the fringes of respectable society), 'demisemiquaver' (a musical note equal to one-sixteenth of a whole note), 'demigorgon' (a powerful demon in mythology)

24. Gen - 'generation' (a group of individuals born and living at the same time), 'genetic' (relating to genes or heredity), 'indigenous' (originating or occurring naturally in a particular place), 'regenerate' (to grow or develop again), 'genocide' (the deliberate killing of a large group of people, especially those of a particular ethnic group or nation)

25. Mega - 'megabyte' (a unit of digital information storage), 'megaphone' (a device used to amplify sound), 'megalith' (a large stone monument), 'megastar' (a very famous and popular person), 'megaton' (a unit of explosive power)

26. Ortho - 'orthodontist' (a dentist specializing in braces and teeth alignment), 'orthodox' (conforming to established beliefs or traditions), 'orthopedic' (relating to the treatment of deformities or injuries of the bones or muscles), 'orthography' (the correct spelling of words), 'orthographic' (relating to correct spelling or projection)

27. Paleo - 'paleontology' (the study of prehistoric life through fossils), 'paleolithic' (relating to the Stone Age), 'paleoecology' (the study of ancient ecosystems), 'paleoclimate' (the climate of the past), 'paleoanthropology' (the study of human evolution)

28. Patho - 'pathology' (the study of diseases and their causes), 'pathological' (relating to or caused by disease), 'empathy' (the ability to understand and share the feelings of others), 'pathogen' (a bacterium, virus, or other microorganism that can cause disease), 'psychopath' (a person with a personality disorder)

29. Soci - 'sociology' (the study of human society and social behavior), 'society' (a group of individuals living together in a community), 'sociable' (friendly and outgoing), 'socialize' (to interact with others), 'socialism' (a political and economic theory)

30. Zo - 'zoology' (the scientific study of animals), 'zoologist' (a person who studies animals), 'zoo' (a place where animals are kept for public viewing), 'zodiac' (a belt of the celestial sphere containing the twelve signs of the zodiac), 'zoomorphic' (having the form of an animal)