The most common and most likely answer to this crossword clue is the 7 letter word DRAINED
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The straight part
We know that "Exhausted" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case exhausted = drained.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DRAINED mean?
DRAINED verb- To lose liquid.
- To flow gradually.
- To cause liquid to flow out of.
- To convert a perennially wet place into a dry one.
- To deplete of energy or resources.
- To draw off by degrees; to cause to flow gradually out or off; hence, to exhaust.
- To filter.
- To fall off the bottom of the playfield.
- Lacking motivation and energy; very tired; knackered.
- Of a battery, empty of charge; discharged.