The most common and most likely answer to this crossword clue is the 5 letter word BONCE
I've seen this crossword clue in The Daily Telegraph
B
O
N
C
E
More clues leading to the result BONCE
- Nut heading for coffee in Costa, say
- Nut formerly supporting bishop
- Head – top of cerebellum encased by skull, say?
- Head cold in skull, perhaps?
- Head? Head of Balliol, formerly
- Head is part of body catching cold
- Springiness not uniform in loaf
- Head cold in cranium, for example?
- Ally constant in axis, say
- Return non-uniform loaf
Buddy explains!

The straight part
We know that "Head" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case head = bonce.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 BONCE mean?
BONCE noun- (British slang) the human head
- The kind of marble used in the game of bonce about.