snake in the grass

Definition

A hidden enemy.

Etymology

Calque of Latin latet anguis in herbā (literally “a snake hides in the grass”), from Eclogue III by the Roman poet Virgil (traditionally 70 – 19 B.C.E.). Compare Dutch addertje onder het gras.

Example Sentences

• "The trouble is, I trusted him too much from the start. He has proved to be a snake in the grass."
• "Is he not here to throw us out—a thief, a spy, a snake in the grass?"
• "He's a snake in the grass, I tell you guys / He may look dumb but that's just a disguise / He's a mastermind in the ways of espionage."