Irregular soldiers tense? A bit (7)
I believe the answer is:
oddment
'a bit' is the definition.
(I've seen this before)
'irregular soldiers tense?' is the wordplay.
'irregular' becomes 'odd'.
'soldiers' becomes 'men' (I've seen this before).
'tense?' becomes 't' (abbreviation used in many dictionaries).
'odd'+'men'+'t'='ODDMENT'
(Other definitions for oddment that I've seen before include "a bit spare" , "Scrap" , "Remnant" , "One of a broken set" , "Piece left over, no match" .)