Gestures of soldiers turning up with poles (5)
I believe the answer is:
signs
'gestures' is the definition.
(I know this)
'soldiers turning up with poles' is the wordplay.
'soldiers' becomes 'GIs' (GI is an informal term for a US soldier).
'turning up' says the letters should be written in reverse.
'with' is a charade indicator (letters next to each other).
'poles' becomes 'NS' (North and South poles).
'gis' back-to-front is 'sig'.
'sig'+'ns'='SIGNS'
'of' acts as a link.
(Other definitions for signs that I've seen before include "Endorses" , "Notices; gestures" , "Sings (anag.)" , "Signals" , "Marks" .)