The most common and most likely answer to this crossword clue is the 10 letter word BALACLAVAS
I've seen this crossword clue in Financial Times
B
A
L
A
C
L
A
V
A
S
Buddy explains!
The straight part
We know that "An IRA man’s overheads" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case an ira man’s overheads = balaclavas.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 BALACLAVAS mean?
BALACLAVAS noun- A warm cap shielding the neck and head, often made out of wool.
- A ski mask with holes for the eyes and, sometimes, the nose and mouth, which may be rolled up and worn like a toque or pulled over the face for greater protection.