The Collaborative International Dictionary of English v.0.48:

Subdual \Sub*du"al\, n.
   Act of subduing. --Bp. Warburton.
   [1913 Webster] Subduce

Moby Thesaurus II by Grady Ward, 1.0:

82 Moby Thesaurus words for "subdual":
   Cadmean victory, KO, Pyrrhic victory, Waterloo, ascendancy,
   beating, breaking, censorship, championship, collapse, conquering,
   conquest, crackdown, crash, crushing, deathblow, debacle, defeat,
   destruction, domestication, downfall, drubbing, easy victory,
   extinguishment, failure, fall, gentling, grand slam, hiding,
   humbling, humiliation, knockout, lambasting, landslide,
   landslide victory, lathering, licking, mastery, moral victory,
   overcoming, overthrow, overturn, picnic, pushover, putting down,
   quashing, quelling, quenching, quietus, reduction, repression,
   ruin, runaway victory, smash, smashing, smothering, squashing,
   squelching, stifling, strangling, subduing, subjugation, success,
   suffocating, suppression, taming, thrashing, throttling,
   total victory, treading down, trimming, triumph, trouncing,
   undoing, vanquishment, victory, walkaway, walkover, whipping, win,
   winning, winning streak