What is the meaning of 蝮?

Synonym of 日本蝮 (Nihon mamushi, “mamushi (Gloydius blomhoffii)”)

person who is feared by others but gives no harm (Can we verify this sense?)

Short for 蝮指 (mamushi-yubi, “a finger with a bent first joint; a finger that can be freely bent”).

Source: wiktionary.org

See also