A painless sore or ulcer, especially the initial lesion of syphilis or other infectious disease; the first sign of these infections.
From French chancre, from Latin cancer meaning 'crab' (the disease was thought to eat at the body like a crab); related to the modern word cancer.
Chancre comes from cancer because medieval doctors thought syphilis 'ate away' at tissue like a crab—that animal metaphor for disease destruction has stuck for 500 years!
Complete word intelligence in one call. Free tier — 50 lookups/day.