triggerman

[trig-er-muh n, -man] /ˈtrɪg ər mən, -ˌmæn/
noun, plural triggermen
[trig-er-muh n, -men] /ˈtrɪg ər mən, -ˌmɛn/ (Show IPA). Informal.
1.
a gangster who specializes in gunning people down.
2.
a bodyguard, especially of a gangster.
Also called trigger.
Origin
1920-25; trigger + man1
British Dictionary definitions for trigger man

triggerman

/ˈtrɪɡəˌmæn/
noun (pl) -men
1.
a person, esp a criminal, who shoots another person
Slang definitions & phrases for trigger man

trigger man

noun phrase

A gunman; hit man, trigger (1920s+ Underworld)