Why is the ninth month called September?
Old English feortan, ultimately from PIE *perd- (cf. Old High German ferzan, Old Norse freta, Sanskrit pard, Greek perdein, Lithuanian perdzu, Russian perdet), of imitative origin. Related: Farted; farting. As a noun, from late 14c.
Clatterer or clatterfart, which wyl disclose anye light secreate. [Richard Huloet, "Abecedarium Anglo-Latinum," 1552.]