Beer about four makes one animated (5)
I believe the answer is:
alive
'one animated?' is the definition.
(I've seen this before)
'beer about four' is the wordplay.
'beer' becomes 'ale' (type of beer).
'about' is an insertion indicator.
'four' becomes 'IV' (Roman numerals).
'ale' going around 'iv' is 'ALIVE'.
'makes' acts as a link.
(Other definitions for alive that I've seen before include "Not yet pushing up the daisies" , "Still kicking, say" , "answer, as it happens" , "In existence" , "Vital, vibrant" .)