Government of army unit lacking time (7)
I believe the answer is:
regimen
'government' is the definition.
(I've seen this before)
'army unit lacking time' is the wordplay.
'army unit' becomes 'regiment' (regiment is a kind of army unit).
'lacking' suggests deleting specific letters.
'time' becomes 't' (abbreviation).
'regiment' with 't' taken away is 'REGIMEN'.
'of' acts as a link.
(Other definitions for regimen that I've seen before include "Prescribed system of diet and exercise - mere gin (anag)" , "Prescribed course of diet, exercise, etc" , "Recommended course" , "Systematic course of treatment, diet, etc" , "Disciplined system" .)