Habits of one government department (7)
I believe the answer is:
customs
'habits' is the definition.
The definition and answer can be both acts as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'one government department' is the wordplay.
I cannot really see how this works, but
'one' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
'government' could be 'us' (U.S. government is an example) and 'us' is found in the answer.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for customs that I've seen before include "state's duties?" , "Port/airport department" , "Import/export duties" , "Traditional ways" , "Import duties" .)