- Congestion
- Conniver
- Connubial
- Conquer
- Conquering
- Consecution
- Consecutive
- Consecutively
- Consent
- Consequence
- Consequent
- Conspicuous
- Constable
- Constipate
- Constipation
- Constitution
- Constitutional
- Constraint
- Constriction
- Construction
- Constructive thinking
- Consuetude
- Consul
- Consular
- Contemplation
- Contemplativeness
- Contemporaneity
- Contemporaneous
- Contemptuous
- Content
- Contest
- Contiguous
- Continent
- Continual
- Continuance
- Continuum
- Contraception
- Contractile
- Contractile vacuole
- Contraction
- Contracture
- Contradict
- Contradiction in terms
- Contraindication
- Contrariety
- Convene
- Convener , convenor
- Convent
- Convergent
- Conversational
- Conversationalist
- Converter
- Cooling
- Coolly
- Coon
- Coop
- Cooperation
- Cooperative
- Coordinated
- Coordinator
- Copacetic
- Copasetic
- Copper
- Copper coin
- Copper-coloured
- Coppice
- Corn circle
- Corn factor
- Corn-cob
- Cornice
- Coromandal coast
- Coronary arteries
- Corrosion
- Corrugated iron
- Corsair
- Coruscate
- Corvette
- Cosmetic
- Cosmic rays
- Cosmogony
- Cosmopolitan
- Cosmopolite
- Cosset
- Cost
- Cost of living
- Croaky
- Cosumed
- Cot with coir matting
- Cote
- Cotton
- Cotton cake
- Cotton on to
- Cotton wool
- Couch potato
- Cough
- County court
- County town
- Coupe
- Coupe de etat
- Couplate