Meaning

adjective lasting, open, or operating through the whole night

adverb during or for the length of one night

adverb happening in a short time or with great speed

originInherited from Middle English overnyght, from Old English ofer niht (“through the night, overnight”), equivalent to over + night. Verbal use (late 19th c.) may have been influenced by German übernachten (16th c.), though it could also have developed independently. Compare also Dutch overnachten (“to overnight”), Middle Low German ȫvernachten (“to overnight”), West Frisian oernachtsje (“to…

Etymology from Wiktionary, CC BY-SA 3.0