Soldiers kid rarely at the borders (8)
I believe the answer is:
infantry
'soldiers' is the definition.
(I've seen this before)
'kid rarely at the borders' is the wordplay.
I cannot quite understand how this works, but
'kid' could be 'infant' (infant is a kind of kid) and 'infant' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for infantry that I've seen before include "Foot-soldiers" , "Grunts" , "Unmounted fighters" , "Troops" , "Men fighting" .)