Definition from Wiktionary, the free dictionary
- Used other than as an idiom: see killer, instinct.
- (idiomatic) The natural inclination to do whatever is necessary to succeed (including extreme violence)
2011 January 25, Les Roopanarine, “Wigan 1 - 2 Aston Villa”, in BBC:
- Not for the first time this season, that lack of killer instinct - combined with an approach more responsive than probing - proved costly for Martinez's men.