Being grassy, is suitable for raising deer (4)
I believe the answer is:
reed
'being grassy is suitable' is the definition.
I can't tell whether this defines the answer.
'raising deer' is the wordplay.
'raising' is a reversal indicator (in a down clue, letters go up).
'deer' back-to-front is 'REED'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for reed that I've seen before include "Marsh plant for deer" , "Slender grass of wet areas" , "Carol" , "Tall grass that grows in swamps" , "'It vibrates in a clarinet, say (4)'" .)