steel trap

steel′ trap′

n. a trap for catching animals, consisting of spring-operated steel jaws with sharp projections that clamp shut. [1725–35]

Thesaurus

Noun	1.	steel trap - an acute intelligence (an analogy based on the well-known sharpness of steel traps); "he's as sharp as a steel trap"; "a mind like a steel trap"keenness, sharpness, acuity, acuteness - a quick and penetrating intelligence; "he argued with great acuteness"; "I admired the keenness of his mind"
	2.	steel trap - a trap made of steel with a strong spring and sharp toothlike projections to hold the preytrap - a device in which something (usually an animal) can be caught and penned