Grassland in southeast provides cover (7)
I believe the answer is:
sheathe
'cover' is the definition.
(to sheathe something is to cover it)
'grassland in southeast' is the wordplay.
'grassland' becomes 'heath' (I am not sure about this - if you are sure you should believe this answer much more).
'in' indicates putting letters inside.
'southeast' becomes 'SE' (synonyms).
'heath' inserted inside 'se' is 'SHEATHE'.
'provides' acts as a link.
Can you help me to learn more?
(Other definitions for sheathe that I've seen before include "Encase in protection" , "Cover in case" , "Protective cover, for sword say" , "Put into scabbard" , "Put (a sword) into case" .)