Wet weather keeps artist at home (4)
I believe the answer is:
rain
'wet weather' is the definition.
(rain is wet weather)
'artist at home' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'ra'+'in'='RAIN'
'keeps' acts as a link.
(Other definitions for rain that I've seen before include "Falling water" , "bad weather" , "Precipitation" , "Cats and dogs?" , "The ---, it ---eth every day (T.Night)" .)