(1) SYN: Stewart-Holmes sign. (2) generally, any phenomenon in which a variable that has been displaced from its normal state by a disturbing influence temporarily deviates from normal in the opposite direction when the disturbing influence is suddenly removed, before finally stabilizing at its normal state, i.e., a phenomenon involving undershoot; e.g., the subsequent hypoglycemia that may follow injection of glucose, because the initial hyperglycemia caused excessive secretion of insulin.