The most common and most likely answer to this crossword clue is the 7 letter word WRINGER
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The straight part
We know that "Mangle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mangle = wringer.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 WRINGER mean?
WRINGER noun- One who wrings.
- A device for drying laundry consisting of two rollers between which the wet laundry is squeezed (or wrung); a mangle.
- Something that causes pain, hardship, or exertion; an ordeal.