Why is the ninth month called September?
1640s, from Latin effluvium "a flowing out," from effluere (see effluence).
effluvium ef·flu·vi·um (ĭ-flōō'vē-əm)n. pl. ef·flu·vi·ums or ef·flu·vi·a (-vē-ə)
A shedding, especially of hair.
An exhalation, especially one of bad odor or injurious influence. No longer in technical use.