ADJ. big, major Overdoses were the single biggest killer among the city's young. | real I don't care what they ask me if it helps them find the real killer. | alleged | convicted | notorious | brutal, vicious | crazed, psychopathic | mass, serial | contract, hired | child, wife, etc. a convicted child killer | giant (figurative) Salford Juniors proved to be the giant killers in last week's semi-finals (= by beating a much better team).
VERB + KILLER hunt, track down | catch, find
KILLER + VERB strike The killer has struck again.
KILLER + NOUN bug, disease, virus Heart attacks have become Britain's No. 1 killer disease. | instinct (figurative) He plays well but still lacks the killer instinct. | blow (figurative) Owen delivered the killer blow soon after half-time.