Why is the ninth month called September?
1520s, "to recount, tell," from Middle French relater "refer, report" (14c.) and directly from Latin relatus, used as past participle of referre "bring back, bear back" (see refer), from re- "back, again" + latus (see oblate (n.)).
Meaning "stand in some relation; have reference or respect" is from 1640s; transitive sense of "bring (something) into relation with (something else)" is from 1690s. Meaning "to establish a relation between" is from 1771. Sense of "to feel connected or sympathetic to" is attested from 1950, originally in psychology jargon. Related: Related; relating.