Etymograph

English

slack

Slack comes from Middle English slak, and goes back to Proto-Germanic *slakaz.

  1. Proto-Germanicc. 500 BCE–200 CE*slakaz1reconstructed
  2. Proto-West Germanicc. 200–500 CE*slak2reconstructed
  3. Old Englishc. 450–1150slæc1
  4. Middle Englishc. 1150–1500slak1
  5. Englishearliest quotation 1611slack1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English slack
  2. 2 Wiktionary, Old English slæc
  3. Earliest quotation in Wiktionary’s entry: 1611, The Holy Bible, London: […] Robert Barker: “The Lord is not ſlacke cõcerning his promiſe (as…”.

Earlier history uncertain. See Wiktionary.

Lineage

  1. Proto-Germanicc. 500 BCE–200 CE*slakazWiktionary, English slackreconstructed
  2. Proto-West Germanicc. 200–500 CE*slakWiktionary, Old English slæcreconstructed
  3. Old Englishc. 450–1150slæcWiktionary, English slack
  4. Middle Englishc. 1150–1500slakWiktionary, English slack
  5. Englishearliest quotation 1611slackWiktionary, English slack. Earliest quotation in Wiktionary’s entry: 1611, The Holy Bible, London: […] Robert Barker: “The Lord is not ſlacke cõcerning his promiſe (as…”

The story

For sense of coal dust, compare slag.

Full etymology on Wiktionary

Linked words

through Proto-Germanic *slakaz

sludge, slouch

through Old English slæc

slake

Another origin of slack

  1. Proto-Germanicc. 500 BCE–200 CE*slakōną‘to slack, slacken’reconstructed
  2. Old Englishc. 450–1150slacian‘to slacken, make slack’
  3. Middle Englishc. 1150–1500slakken
  4. Englishtodayslack

Another origin of slack

  1. Old Norsec. 800–1350slakki‘a slope’
  2. Middle Englishc. 1150–1500slak
  3. Englishtodayslack

Today it means

noun The part of anything that hangs loose, having no strain upon it.

Sources

Sources: Wiktionary, “slack”; the older steps come from the Wiktionary entry for Old English slæc. 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 *slakaz / slack

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