Soldiers almost take on monument (6)
I believe the answer is:
menhir
'monument' is the definition.
(I know that menhir is a type of monument)
'soldiers almost take on' is the wordplay.
'soldiers' becomes 'men' (men can mean a group of soldiers).
'almost' means to remove the last letter (almost the whole word is kept).
'take on' becomes 'hire' (both can mean to employ).
'hire' with its final letter removed is 'hir'.
'men'+'hir'='MENHIR'
(Other definitions for menhir that I've seen before include "5 Down" , "Ancient upright stone" , "Standing stone" .)