cogent

[L. cogens, p. pr. of cogere to drive together, to force; co- + agere to drive. See Agent, a., and cf. Coact to force, Coagulate, p. a.]

1. Compelling, in a physical sense; powerful. [Obs.]

The cogent force of nature.

2. Having the power to compel conviction or move the will; constraining; conclusive; forcible; powerful; not easily reasisted.

No better nor more cogent reason.

Proofs of the most cogent description.

The tongue whose strains were cogent as commands,
Revered at home, and felt in foreign lands.

Syn. -- Forcible; powerful; potent; urgent; strong; persuasive; convincing; conclusive; influential.

Definition: effective
Antonyms: impotent, ineffective, invalid, weak