c (calorie (small calorie))

C (carbon [element])

C (cytosine)

C (Calorie (kilocalorie) [case sensitive])

C (Celsius (centigrade))

C-B (chest-back)

C-collar (cervical collar)

C-spine (cervical spine)

c.c. (with food (L. cum cibos))

c.m.s. (to be taken tomorrow morning (cras mane sumendus))