Why is the ninth month called September?
1610s, "involving apoplexy," from French apoplectique (16c.), from Latin apoplecticus, from Greek apoplektikos "disabled by a stroke, crippled, struck dumb," from apoplektos, verbal adjective of apoplessein (see apoplexy). Meaning "showing symptoms of apoplexy" (1721) gradually shaded into "enraged, very angry."
apoplectic ap·o·plec·tic (āp'ə-plěk'tĭk)
Relating to, having, or predisposed to apoplexy.