Why is the ninth month called September?
1798, originally in natural history, from Latin aberrantem (nominative aberrans), present participle of aberrare "to wander away, go astray" (see aberration).
aberrant ab·er·rant (ā-běr'ənt, āb'ər-)adj.
Deviating from the usual course, as certain ducts, vessels, or nerves.
Deviating from the normal; untrue to type.
Out of place; ectopic.