"not meriting disapprobation or censure, without fault," late 14c., from blame (n.) + -less. Related: Blamelessly; blamelessness. Seldom-used blameful is recorded from late 14c.
Entries linking to blameless
blame n.
early 13c., "an act or expression of disapproval, rebuke, etc., for something deemed wrong;" mid-14c., "responsibility for something that is wrong, culpability," from Old French blasme "blame, reproach; condemnation," a back-formation from blasmer "to rebuke" (see blame (v.)).
-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.