| concerning(important, significant, consistent, compatible, applicable) |
| concordant(adjective, subject, collateral, interchangeable, attendant) |
| confirmatory(adjective, lower, subject, side, subordinate) |
| conformant(adjective, appropriate, important, proper, significant) |
| conforming(important, significant, consistent, compatible, applicable) |
| congruent(important, significant, consistent, compatible, applicable) |
| congruous(adjective, good, correct, right, appropriate) |
| consistent(important, significant, compatible, applicable, germane) |
| consonant(adjective, appropriate, important, proper, significant) |
| contingent |
| continuation |
| coordinate(adjective, side, subordinate, secondary, interchangeable) |
| corollary |
| correlated(important, significant, consistent, organized, relevant) |
| correlative(adjective, relation, organized, interchangeable, proportionate) |
| correspondent(adjective, appropriate, important, proper, significant) |
| corresponding(adjective, side, subordinate, secondary, interchangeable) |
| expedient(adjective, appropriate) |
| extrapolation |
| felicitous(adjective, appropriate) |