A beam bringing soldiers to a sticky end? (3)
I believe the answer is:
ray
'a beam' is the definition.
(synonyms)
'soldiers to a sticky end?' is the wordplay.
'soldiers' becomes 'ra' (abbreviation for Royal Artillery**).
'end?' indicates one should take the final letters (I've seen 'ending' mean this).
The final letter of 'sticky' is 'y'.
'ra'+'y'='RAY'
'bringing' is the link.
(Other definitions for ray that I've seen before include "Shaft of light" , "A bright beam or flat fish" , "Lindwall" , "Flatfish or sunbeam" , "Second note for the flat fish" .)