Outgains rhymes with:
alkanes, arellanes, bloodstains, cobain's, hurricane's, hurricanes, kardashian's, magallanes, membranes, messiaen's, migraines, monoplanes, santillanes, sarbanes, warplanes, windowpanes
Outgains sounds like:
outcomes, outgaining, outgoing, outguessing, outgunning, outguns, outshines, outshining, outweighing