Synonyms for Vanquish:

n.

knock out. prevail against, lick, trim, subjugate, best, ace. smear, cream, clobber, massacre, overwhelm, shellac, annihilate, wallop, drub, steamroller. conquer (noun)
study at defeat.
vanquish (noun)
trounce, beat, crush, beat out, shell.

v.

defeat soundly (verb)
rout, overcome, crush, surmount, overwhelm, overturn, humble, conquer, overpower, subjugate, beat, quell, subdue.
dominate (verb)
dominate, succeed, better, oppress, prevail, subordinate, oversee, control, command, lord, rule, preside.

Other synonyms:

shellac. clobber, steamroller. drub, cream, wallop. lick, annihilate, smear. overwhelm. trim. countermove
checkmate.
lick
trounce.
wallop
shellac, wallop.
Other relevant words:
clobber, ace, beat out, lick, cream, drub, trim, smear, prevail against, wallop, shell, steamroller, subjugate, shellac, overwhelm, massacre, best, annihilate.

Usage examples for vanquish

  1. Both these men were considered excellent swordsmen, but when Beauchamp heard again the little gray man's " a mort, mon fils," he shuddered, and the little hairs at the nape of his neck rose up, and his spine froze, for he knew that he had heard the sentence of death passed upon him; for no mortal had yet lived who could vanquish such a swordsman as he who now faced him. – The Outlaw of Torn by Edgar Rice Burroughs
  2. You did not set forth that we might vanquish Sardinia, but that our foes might conquer Africa. – The Scarlet Banner by Felix Dahn