ˈfrenyələm noun
also frae·nu·lum ˈfrēnyə-, ˈfrenyə-
( plural frenu·la also fraenu·la -lə)
Etymology: New Latin, diminutive of Latin frenum, fraenum
1. : a frenum especially when small ; specifically : a narrow band of white matter in the brain running between the upper surface of the anterior medullary velum and the corpora quadrigemina
2. : a bristle or group of bristles on the front edge of the posterior wings of many lepidopterous insects that interlocks with a process on the front wings and thus unites the wings