Time to encounter sorceress in the grass (6)
I believe the answer is:
twitch
'grass' is the definition.
(I've seen this before)
'time to encounter sorceress' is the wordplay.
'time' becomes 't'.
'to encounter' means one lot of letters go next to another.
'sorceress' becomes 'witch' (I've seen this before).
't'+'witch'='TWITCH'
'in the' is the link.
(Other definitions for twitch that I've seen before include "Muscle spasm" , "Nervous action" , "Sudden muscular spasm" , "involuntary response" , "grass" .)