Stone slab in battle ground (6)
I believe the answer is:
tablet
'stone slab' is the definition.
(I've seen this before)
'battle ground' is the wordplay.
'ground' is an anagram indicator ('grind' the letters into a new form).
'battle' with letters rearranged gives 'TABLET'.
'in' is the link.
(Other definitions for tablet that I've seen before include "Prescription" , "Medicine - flat slab - computer" , "Small bar of soap" , "Weekly" , "PC" .)