(frenum, frenulum) n. 1. any of the folds of mucous membrane under the tongue or between the gums and the upper or lower lips. 2. any of several other structures of similar appearance.
(tongue-tie) n. a congenital anomaly in which an unusually short, thick, or tight *fraenum restricts the mobility of the tongue. It is often first noticed in a newborn who has difficulty breastfeeding. No treatment is required unless the condition is extreme, in which case surgical division of the fraenum may be necessary.... ankyloglossia