1. [late 19C] (sporting, also bone-breaker) a large-calibre sporting rifle, used on large game.
2. [late19C-1960s] (US, also bone-bender, bone-cracker) a wrestler; a powerful fist.
3. [1960s–70s] (US) a person who shakes hands forcefully; thus a powerful handshake.
4. [1970s+] (US prison) a large knife.
5. [1990s+] in drug contexts.
(a) a near-overdose in which the user feels as if the injection they have just taken is crushing their bones; thus bone-crushing adj.
(b) painful withdrawal symptoms.
(c) crack cocaine.
6. [2000s] a prison guard who uses physical force.