Other forms: overslept, oversleeping, oversleeps
To oversleep is to stay in bed past the time you meant to get up. The alarm went, or it did not, and either way you are late.
It works without an object, and the past is overslept. It is one of the standard excuses of working life and one of the few that everybody accepts, since it has happened to everybody. The related nouns are a lie-in, which is deliberate and pleasant, and a missed alarm, which is what people say when they want to blame the phone.
1verboversleepTo sleep longer than you intended.
“Set two alarms if you are worried you will oversleep.”
Proto-Germanic
*slēpaną — to sleep
Proto-West Germanic
*slāpan
ang-ang
slēpan
Middle English
slepen
English
sleep
English, today
oversleep
From over- + sleep. sleep comes from Middle English slepen, from ang-ang slēpan (ang-wsx slǣpan), from Proto-West Germanic slāpan, from Proto-Germanic slēpaną (“to sleep”). 2 Cognate with frr sleepe, sliap, sliip, släipe (“to sleep”), stq släipe (“to sleep”), West Frisian sliepe (“to sleep”), gsw schlaaffe, schlaafä, schlafe, schloafe, schloafen, schlofe, schlàfu (“to sleep”), bar schlofn, schlåfn, sghlofn (“to sleep”), gmw-cfr schlofe (“to sleep”), cim slaafan, slafan, slavan (“to sleep”), Dutch and Low German slapen (“to sleep”), German schlafen (“to sleep”), li schloëpe, slaope (“to sleep”), lb schlofen (“to sleep”), mhn schloven (“to sleep”), wym šłȫfa, śłöfa (“to sleep”), Yiddish שלאָפֿן (“to sleep”), gme-cgo schlipen (“to sleep”), Gothic 𐍃𐌻𐌴𐍀𐌰𐌽 (“to sleep”).
Etymology from Wiktionary, CC BY-SA