- Conservation biology
- Conservator
- Conservatory
- Considerate
- Consist
- Consistency, consistence
- Consoles
- Consolidate
- Consultant
- Consumed
- Consumer
- Consummation
- Consumptive
- Contact
- Container
- Containing
- Containing 12
- Contemn
- Contravention
- Contribute
- Contributor
- Contrite
- Controls
- Controversialist
- Contumely
- Coprology
- Cool wind
- Cooler
- Cooper
- Cop out
- Coparcenor
- Coper
- Copier
- Copious
- Copiousness
- Copper plate
- Copper sulphate
- Copper vessel
- Copra
- Corrugate
- Corsage
- Corselet
- Coruscation
- Coryza
- Cosmetic preparation
- Cosmogonal suktha
- Cosmography
- Cosmological
- Cosmology
- Coumarone
- Counseller
- Counselling
- Countdown
- Counter plea
- Counter-acting
- Coup de grace
- Couple
- Courses
- Court of law
- Courtesies
- Courtliness
- Courtly
- Cowl
- Cowpea pods
- Cows
- Coxswain
- Coy
- Crab
- Crabber
- Crack a joke
- Crack brained
- Cracked
- Cracking sound
- Craftiness
- Creeper
- Creepers
- Cremation
- Creme
- Creole
- Crepe
- Crept
- Crest
- Cretin
- Crevasse
- Crevice
- Criminal
- Criminalist
- Croft
- Crom
- Crookedness
- Croon
- Crooner
- Crop
- Cropper
- Croquet
- Crores
- Cross armed
- Cross contamination
- Cross purpose
- Cross-country