Collins COBUILD Advanced Learner's English Dictionary - sniff out

1. If you sniff out something, you discover it after some searching. (INFORMAL) ...journalists who are trained to sniff out sensation or scandal. PHRASAL VERB: V P n (not pron) 2. When a dog used by a group such as the police sniffs out hidden explosives or drugs, it finds them using its sense of smell. A police dog, trained to sniff out explosives, found evidence of a bomb in the apartment. PHRASAL VERB: V P n (not pron), also V n P