c. 1300, "uninjured," from harm (n.) + -less. Meaning "without power or disposition to harm" is from 1530s. Related: Harmlessly; harmlessness.
Entries linking to harmless
harm n.
Old English hearm "hurt, pain; evil, grief; insult," from Proto-Germanic *harmaz (source also of Old Saxon harm, Old Norse harmr "grief, sorrow," Old Frisian herm "insult; pain," Old High German harm, German Harm "grief, sorrow, harm"), from PIE *kormo- "pain." To be in harm's way is from 1660s.
-less
word-forming element meaning "lacking, cannot be, does not," from Old English -leas, from leas "free (from), devoid (of), false, feigned," from Proto-Germanic *lausaz (cognates: Dutch -loos, German -los "-less," Old Norse lauss "loose, free, vacant, dissolute," Middle Dutch los, German los "loose, free," Gothic laus "empty, vain"), from PIE root *leu- "to loosen, divide, cut apart." Related to loose and lease.