Antonyms of adj slaughterous

1 sense of slaughterous

Sense 1
gory, sanguinary, sanguineous, slaughterous, butcherly -- (accompanied by bloodshed; "this bitter and sanguinary war")

INDIRECT (VIA bloody) -> bloodless -- (free from blood or bloodshed; "bloodless surgery"; "a bloodless coup")

Similarity of adj slaughterous

1 sense of slaughterous

Sense 1
gory, sanguinary, sanguineous, slaughterous, butcherly -- (accompanied by bloodshed; "this bitter and sanguinary war")
       => bloody (vs. bloodless) -- (having or covered with or accompanied by blood; "a bloody nose"; "your scarf is all bloody"; "the effects will be violent and probably bloody"; "a bloody fight")