| certain(correct, honest, straight, real, genuine) |
| classic(adjective, simple, bright, clean, plain) |
| cleanly |
| clear(adjective, sound, reasonable, clean, sensible) |
| cogent(clear, sound, reasonable, sensible, rational) |
| coherent(clear, sound, reasonable, sensible, rational) |
| comestible |
| comme il faut(expression, idiom, right, modest, polite) |
| common(pleasant, fair, agreeable, suitable, adequate) |
| commonsensical(clear, sound, reasonable, sensible, rational) |
| compelling(clear, sound, reasonable, sensible, rational) |
| competent |
| compulsive |
| concordant |
| confirmed(good, sound, right, reasonable, certain) |
| conforming(right, modest, polite, suitable, decent) |
| conformist |
| congruent(clear, sound, reasonable, sensible, rational) |
| consequent(clear, sound, reasonable, sensible, rational) |
| consistent(clear, sound, reasonable, sensible, rational) |