(1) at fluoroscopy, a test for diaphragmatic function; paradoxic motion of a hemidiaphragm when a patient sniffs vigorously shows phrenic nerve paralysis or paresis of the hemidiaphragm. (2) Occurrence of a fishlike odor with potassium hydroxide treatment of vaginal discharge; one of the Amsel criteria for clinical diagnosis of bacterial vaginosis. SYN: whiff test (2).
