Cryptic crossword clue
Joint leader is a fool

The most common and most likely answer to this crossword clue is the 11 letter word KNUCKLEHEAD

I've seen this crossword clue in The Guardian
K
N
U
C
K
L
E
H
E
A
D

Buddy explains!

The straight part
We know that "fool" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fool = knucklehead.
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 KNUCKLEHEAD mean?

KNUCKLEHEAD noun
  1. An idiot; a stupid or inept person
  2. An endearing remark directed to siblings or one's own children; a child who is acting silly.

Latest crossword clues with full explanations