Painless
来自Big Physics
wiktionary
From Middle English paynles, peynlees, equivalent to pain + -less. Compare West Frisian pynleas(“painless”), Dutch pijnloos(“painless”).
etymonline
painless (adj.)
mid-15c., peineles (adj. and adv.) "suffering no pain; in a painless manner," from pain (n.) + -less. Related: Painlessly; painlessness.
