Gardeners working across wide grass-covered ground (10)
I believe the answer is:
greensward
'grass-covered ground' is the definition.
'greensward' can be an answer for 'ground' (greensward is a kind of ground). I am not sure about the 'grass-covered' bit.
'gardeners working across wide' is the wordplay.
'working' indicates anagramming the letters.
'across' means one lot of letters goes inside another.
'wide' becomes 'w' (abbreviation e.g. in cricket).
'gardeners' with letters rearranged gives 'greensard'.
'greensard' going around 'w' is 'GREENSWARD'.
Can you help me to learn more?
(Other definitions for greensward that I've seen before include "mostly turf" , "Lawn" , "Grass covered ground" .)