- Centaurea imperialis
 - Cotula coronopifolia
 - cape marigold
 - China aster
 - Consolida ambigua
 - Cheiranthus asperus
 - cosmea
 - Chrysanthemum leucanthemum
 - Cheiranthus cheiri
 - candytuft
 - cross infection
 - cowpie
 - cattle plague
 - catarrhal fever
 - chronic wasting disease
 - costiasis
 - canine chorea
 - camelpox
 - chorea
 - creeps
 - Cupid's disease
 - Cupid's itch
 - condensation pump
 - capital of liechtenstein
 - childbirth
 - cytosmear
 - cytologic smear
 - Cox_2 inhibitor
 - chemical phenomenon
 - common corn salad
 - capital of malta
 - corroborative
 - cardiac valve
 - cardiopathy
 - carnivorous bat
 - carl van doren
 - carl clinton van doren
 - costal groove
 - coccidioidomycosis
 - coccidiomycosis
 - Chartism
 - characteristic root of a square matrix
 - commodore vanderbilt
 - cornelius vanderbilt
 - chouse
 - cobwebby
 - chitterlings
 - chitlins
 - chance variable
 - capital of the united states