The garment for a masterly company head? (3)
I believe the answer is:
mac
'the garment' is the definition.
(mac is a kind of garment)
'masterly company head?' is the wordplay.
'masterly' becomes 'ma' (I can't justify this - if you can you should give a lot more credence to this answer).
'head?' says to take the initial letters (I've seen 'heading' mean this (head could mean the top letter)).
The first letter of 'company' is 'c'.
'ma'+'c'='MAC'
'for a' is the link.
Can you help me to learn more?
(Other definitions for mac that I've seen before include "Waterproof coat (colloq.)" , "Overcoat" , "PC" , "Raincoat (colloq.)" , "A rainproof" .)