traps (n.1)

"expanse of dark igneous rock," 1794, from Swedish trapp (Torbern Bergman, 1766), from trappa "stair," related to Middle Low German trappe "staircase" (see trap (n.)). So called from the step-like appearance of the rock.

"drums, cymbals, bells, etc.," 1925, from earlier trap drummer (1903) "street musician who plays a drum and several other instruments at once," perhaps from traps "belongings" (1813), shortened form of trappings.