Synonyms for Stun:

n.

put to sleep, flash mob, spring a surprise, drug, stagger, shake up, knock out, HIT. maze, thump, punch, batter, beat up, awareness, bemuse, smack, bludgeon. numb, wither, petrify, affect. stun (noun)
floor, stupefy, sandbag, bedaze, take aback, ball over, blow out of the water, shock, daze.

v.

amaze (verb)
daze, overwhelm, dazzle, astonish, surprise, amaze, astound, impress, bewilder.
change (verb)
stupefy.
contact (verb)
sandbag.
disable (verb)
stupefy, botch, incapacitate, neutralize, undermine, invalidate, hamstring, hamper, deaden, hinder, benumb, impair, hobble, abrogate, vitiate, dull, lame, screw up, enfeeble, cripple, paralyze, disarm, handicap, anesthetize, sap, cramp, disable, weaken, tamper, scotch, prostrate.
shock (verb)
daze, petrify, surprise, astonish, knock out, overwhelm, astound, stupefy, floor, paralyze, stagger, shake up, amaze, bemuse, HIT, bewilder.
surprise (verb)
jolt, take aback, shock, catch unawares, startle.

Other synonyms:

bludgeon, flash mob, stagger, bemuse. punch, numb, beat up. thump, petrify, wither. batter. smack. knock out. HIT. amaze
astound.
confuse
bemuse.
frighten
petrify.
surprise
amaze, astonish.
Other relevant words:
floor, batter, bemuse, bedaze, numb, wither, maze, drug, sandbag, ball over, bludgeon, blow out of the water, put to sleep, smack, stagger, HIT, punch, petrify, shake up.

Usage examples for stun

  1. On top of the hull thing stood a rarin' angry brute, illustratin' the cap- stun and completed mission of the whiskey bottle. – Around the World with Josiah Allen's Wife by Marietta Holley
  2. They could have told him it was just one more hour in which the Grim Reaper could steal closer and make ready to strike a blow that would stun the entire civilized world! – Dave Dawson at Casablanca by Robert Sydney Bowen
  3. But he in his eagerness paused for no answer, but went on to stun Monsieur with statements new and amazing to his ear. – Helmet of Navarre by Bertha Runkle