n 1 : a curving or doubling of a line so as to form a closed or partly open curve within itself through which another line can be passed 2 a : something (as an anatomical part) shaped like a loop - see LOOP OF HENLE LIPPES LOOP b : a surgical electrode in the form of a loop 3 : a fingerprint in which some of the papillary ridges make a single backward turn without any twist 4 : a wire usu. of platinum bent at one end into a small loop (usu. four millimeters in inside diameter) and used in transferring microorganisms .
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