Vanquish, v. t. [imp. & p. p. Vanquished; p. pr. & vb. n. Vanquishing.]
Etymology: [OE. venquishen, venquissen, venkisen,F. vaincre, pret. vainquis, OF. veintre, pret. venqui, venquis (cf. an OF. infin. vainquir), fr. L. vincere; akin to AS. wig war, battle, wigant a warrior, wigan to fight, Icel. vig battle, Goth. weihan to fight, contend. Cf. Convince, Evict, Invincible, Victor.]
1. To conquer, overcome, or subdue in battle, as an enemy. Hakluyt. They . . . Vanquished the rebels in all encounters. Clarendon.
2. Hence, to defeat in any contest; to get the better of; to put down; to refute. This bold assertion has been fully vanquished in a late reply to the Bishop of Meaux's treatise. Atterbury. For e'en though vanquished, he could argue still. Goldsmith.
Syn. -- To conquer; surmount; overcome; confute; silence. See Conquer.
1 other Webster entry under this spelling
Vanquish, n. (Far.)
A disease in sheep, in which they pine away. [Written also vinquish.]
Shades of meaning
Fernald has no entry of its own for vanquish; he lists it under beat, conquer.
Where he writes about it:
To defeat an enemy is to gain an advantage for the time; to vanquish is to win a signal victory; to conquer is to overcome so effectually that the victory is regarded as final. — from conquer