English

sleepless

Sleepless comes from Proto-West Germanic *slāp ‘sleep’, and goes back to Proto-Germanic *slēpaz.

Proto-Germanicc. 500 BCE–200 CE*slēpaz¹‘sleep’reconstructed
Proto-West Germanicc. 200–500 CE*slāp²‘sleep’reconstructed
Proto-West Germanicc. 200–500 CE*slāpalaus³reconstructed
Old Englishc. 450–1150slǣplēas⁴
Middle Englishc. 1150–1500slepeles⁴
Englishtodaysleepless⁴

attested reconstructed ? uncertain or disputed deepest recorded ancestor

¹ Wiktionary, Proto-West Germanic *slāp
² Wiktionary, Proto-West Germanic *slāpalaus
³ Wiktionary, Old English slæpleas
⁴ Wiktionary, English sleepless

Lineage

Proto-Germanicc. 500 BCE–200 CE*slēpaz1Wiktionary, Proto-West Germanic *slāp‘sleep’reconstructed
Proto-West Germanicc. 200–500 CE*slāp2Wiktionary, Proto-West Germanic *slāpalaus‘sleep’reconstructed
Proto-West Germanicc. 200–500 CE*slāpalaus3Wiktionary, Old English slæpleasreconstructed
Old Englishc. 450–1150slǣplēas4Wiktionary, English sleepless
Middle Englishc. 1150–1500slepeles4Wiktionary, English sleepless
Englishtodaysleepless4Wiktionary, English sleepless

Formed from sleep + -less

Proto-Germanic *slēpaną ‘to sleep’

Proto-West Germanic *slāpan

Anglian Old English slēpan ‘to sleep’

Middle English slepen ‘to sleep’

English sleep

Linked words

through Proto-West Germanic *slāp ‘sleep’

asleep, slab, 3 more

Today it means

adj Characterized by an absence of sleep: wakeful.

Sources

Sources: Wiktionary, “sleepless”; the older steps come from the Wiktionary entries for Proto-West Germanic *slāp, Proto-West Germanic *slāpalaus, Old English slæpleas. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Germanic *slēpaz / sleepless

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