Why is the ninth month called September?
early 15c., from Middle French ignominieux (14c.) or directly from Latin ignominiosus "disgraceful, shameful," from ignominia "loss of a (good) name," from assimilated form of in- "not, opposite of" (see in- (1)) + nomen (genitive nominis) "name" (see name). Influenced by Old Latin gnoscere "come to know." Related: Ignominiously; ignominiousness.