Wet seed that's no good (4)

I believe the answer is:
rain
'wet' is the definition.
(wet weather)
'seed that's no good' is the wordplay.
I cannot quite see how this works, but
'no' could be 'n' (common abbreviation) and 'n' is present in the answer.
The remaining letters 'rai' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rain that I've seen before include "The ---, it ---eth every day (T.Night)" , "Precipitation" , "Falling water" , "bad weather" , "Pelt" .)
