Synonyms for Harmless:

adj.

innocent (adjective)
lily-white, unblamable.
not injurious or dangerous (adjective)
inoperative, innocuous, simple, naive, innoxious, gentle, powerless, innocent, manageable, kind, reliable, Unoffensive, inoffensive, Hurtless, sure, controllable, sanitary, sound, safe, trustworthy.
safe (adjective)
immune, inviolable, innoxious, secure, sure, protected, safe.

n.

preventable, avoidable, naive, protective, simple, kind. help, Unoffensive, Hurtless. irreproachable, unblamable, lily-white. harmless (noun)
innocuous, uncontroversial, benignant, innocent, nonmalignant, insipid, unoffending, innoxious, inoffensive, benign.

Other synonyms:

Unoffensive, Hurtless, preventable, protective, unblamable, avoidable, kind, controllable. irreproachable, lily-white. sound. ingenuous
naive.

Usage examples for harmless

  1. The Hirlaji are harmless – Warlord of Kor by Terry Gene Carr
  2. You've not even had a perfectly harmless letter from a boy who is just like a brother to you and whom you've known for years." – The Mark Of Cain by Andrew Lang
  3. For in course of time, and under altered circumstances, you may find it a disadvantage that they know even the most harmless things about you. – Counsels and Maxims From The Essays Of Arthur Schopenhauer by Arthur Schopenhauer