The most common and most likely answer to this crossword clue is the 6 letter word CRAZED
I've seen this crossword clue in Independent
C
R
A
Z
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D
More clues leading to the result CRAZED
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The straight part
We know that "Ridiculous" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ridiculous = crazed.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 CRAZED mean?
CRAZED verb- To weaken; to impair; to render decrepit.
- To derange the intellect of; to render insane.
- To be crazed, or to act or appear as one that is crazed; to rave; to become insane.
- To break into pieces; to crush; to grind to powder. See crase.
- To crack, as the glazing of porcelain or pottery.
- Maddened; driven insane.
- Covered with cracks (generally applied to porcelain).