'To smell a rat' definitions:

Definition of 'To smell a rat'

From: GCIDE

Smell \Smell\ (sm[e^]l), v. t. [imp. & p. p. Smelled, Smelt; p. pr. & vb. n. Smelling.] [OE. smellen, smillen, smullen; cf. LG. smellen, smelen, sm["o]len, schmelen, to smoke, to reek, D. smeulen to smolder, and E. smolder. Cf. Smell, n.]
1. To perceive by the olfactory nerves, or organs of smell; to have a sensation of, excited through the nasal organs when affected by the appropriate materials or qualities; to obtain the scent of; as, to smell a rose; to smell perfumes. [1913 Webster]
2. To detect or perceive, as if by the sense of smell; to scent out; -- often with out. "I smell a device." --Shak. [1913 Webster]
Can you smell him out by that? --Shak. [1913 Webster]
3. To give heed to. [Obs.] [1913 Webster]
From that time forward I began to smellthe Word of God, and forsook the school doctors. --Latimer. [1913 Webster]
To smell a rat, to have a sense of something wrong, not clearly evident; to have reason for suspicion. [Colloq.]
To smell out, to find out by sagacity. [Colloq.] [1913 Webster]