Synonyms for Benign:

adj.

advantageous (adjective)
charitable.
beneficial (adjective)
beneficent.
benevolent (adjective)
kindhearted, benignant, goodhearted, liberal.
forgiving (adjective)
clement.
friendly (adjective)
peaceful, peaceable.
good (adjective)
excellent, exemplary, pleasant, favorable, good, admirable, praiseworthy, five-star, first-rate, splendid, worthy, beneficial, topnotch, nice, laudable, worthwhile, fine, commendable.
kindly (adjective)
benevolent, beneficent, genial, benignant, favorable, liberal, amiable, good, gentle, mild, kind, goodhearted, generous.
mild (adjective)
cordial, lenient, tolerant, forbearing, charitable, quiet, insipid, kind, libertarian, sweet, even, mild, tender, peaceful, genial, moderate, amiable, liberal, open-minded, benevolent, permissive, soft, broad-minded, lax, peaceable, gentle, clement, meek.
mild, especially describing weather (adjective)
bright, fortunate, warm.
not cancerous (adjective)
harmless.

n.

acute, autoimmune, communicable, clinical, asymptomatic, advanced, catching, congenital, chronic. goodhearted, warm, altruistic, Warm-hearted, sensitive, attitude, generous, beneficent, caring, kindhearted. brilliant, fair, luck, fortunate, bright. benign (noun)
genial, harmless, nonmalignant, kindly, benignant.
harmless (noun)
innocuous.

Other synonyms:

catching, asymptomatic, autoimmune, clinical, goodhearted, congenital, communicable. fortunate. advanced, acute. bright. brilliant. fair. harmless
harmless.
kindly
kindly.
Other relevant words:
beneficent, Warm-hearted, generous, fortunate, brilliant, warm, caring, bright, altruistic, asymptomatic, kindly, goodhearted, kindhearted, chronic, benignant, nonmalignant, fair, harmless, sensitive, advanced, innocuous.

Usage examples for benign

  1. Nature to these Eskimo is especially benign – The New North by Agnes Deans Cameron
  2. These by a law benign Thou biddest turn again, and render back To thee their fires. – The Consolation of Philosophy by Boethius
  3. Well, you see, said he, with his benign smile, you're the first woman lawyer that's ever been in Westville. – Counsel for the Defense by Leroy Scott