Measures of alcohol for military groups (5)
I believe the answer is:
units
This clue is a double definition.
'measures of alcohol' is the first definition.
(I've seen this before)
'military groups' is the second definition.
(I've seen this in another clue)
'for' is the link.
(Other definitions for units that I've seen before include "Modules" , "Measures of alcohol" , "Individual things as parts of a whole" , "Individual things, like pieces of furniture" , "military teams" .)