Badly steer most of spray over grass (9)
I believe the answer is:
misinform
'badly steer most' is the definition.
I can't judge whether this definition defines the answer.
'spray over grass' is the wordplay.
'spray over' becomes 'mis' (I can't justify this - if you can you should believe this answer much more).
'grass' becomes 'inform' (I've seen this before).
'mis'+'inform'='MISINFORM'
'of' is the link.
Can you help me to learn more?
(Other definitions for misinform that I've seen before include "Give incorrect gen to" , "Deceive" , "Provide with incorrect facts" , "teach badly" , "Tell incorrectly" .)