Definition of "clear up"

clear up

verb
third-person singular simple present clears up, present participle clearing up, simple past and past participle cleared up
1. (transitive) To clarify, to correct a misconception.
2. (intransitive) To depart or disappear.
3. (intransitive, of skin or medical images) To become free of certain blemishes.
4. (intransitive) Of stormy weather, to dissipate, to become calm.
  Quotations
  Advise him to stay a little longer till the weather clears up.
  1731 (date written, published 1745), Jonathan Swift, “Directions to Servants”, in Thomas Sheridan and John Nichols, editors, The Works of the Rev. Jonathan Swift, […], new edition, volume XVI, London: […] J[oseph] Johnson, […], published 1801
5. (UK, transitive, intransitive) To clean up.
  Quotations
  Accepting that incidents will always happen, what then matters is how quickly we can clear up the mess, something British Rail was better at. [...] I would turn up as quickly as possible in the on-call Hillman Avenger and assess how quickly we could clear up.
  2019 October, Ian Walmsley, “Cleaning up”, in Modern Railways, page 43
6. (snooker, billiards, intransitive) To pot all of the remaining balls in a single turn.