Fixed cost of a hat? (8)
I believe the answer is:
overhead
'fixed cost' is the definition.
'overhead' can be an answer for 'cost' (thesaurus). I am not sure about the 'fixed' bit.
'of a hat?' is the wordplay.
I cannot really see how this works, but
'of' could be 'o' and 'o' is found in the answer.
'a' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for overhead that I've seen before include "Cost of upkeep of business premises, etc" , "Aloft" , "Operating cost" , "St Petersburg royal residence" , "A running cost of a business" .)