English painter captures revelry occasionally (8)
I believe the answer is:
landseer
'english painter' is the definition.
(Edwin Landseer, 1802-1873)
'captures revelry occasionally' is the wordplay.
'captures' becomes 'lands' (both can mean to obtain or secure).
'occasionally' means one should take alternating letters.
The alternate letters of 'revelry' are 'eer'.
'lands'+'eer'='LANDSEER'
(Other definitions for landseer that I've seen before include "See 1 down" , "The Monarch of the_Glen painter" , "Artist" , "Send Lear out for the English painter" , "English (animal) painter, d. 1873" .)