The most common and most likely answer to this crossword clue is the 6 letter word WASHER
I've seen this crossword clue in Financial Times
W
A
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More clues leading to the result WASHER
Buddy explains!
The straight part
We know that "Appliance/ring which keeps joints together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case appliance/ring which keeps joints together = washer.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 WASHER mean?
WASHER noun- Something that washes; especially an appliance such as a washing machine or dishwasher.
- A person who washes (especially clothes) for a living; a washerman or washerwoman.
- A flat disk, placed beneath a nut or at some joint, to distribute pressure, alleviate friction or prevent leakage.
- A face cloth.
- To fit (a mechanical device) with a washer.