smell fishy

smell a rat

To sense something suspicious.

smell blood

To sense that one has an advantage over an adversary or rival.

smell like a rose

To be regarded as appealing, virtuous, or respectable; to be untainted or unharmed.

smell like a tart's handbag

To smell strongly of perfume.

smell of an oily rag

A very small amount, or the absolute minimum (usually of money).

smell of the lamp

To bear marks of great study and labor.

smell of the shop

To indicate too distinctively one's occupation or profession.

smell one's own farts

To become conceited; to believe that one's achievements are greater than they really are.