Imbibing beer, team tends at intervals to become angry (10)

'angry' is the definition.
(I've seen this in another clue)

'imbibing beer team tends at intervals' is the wordplay.
'imbibing' means one lot of letters goes inside another (imbibe can mean to drink or absorb).
'beer' becomes 'bitter' (bitter is a type of beer).
'at intervals' means one should take alternating letters (letters are taken at regular intervals).
'team'+'tends'='teamtends'
The alternate letters of 'teamtends' are 'emed'.
'bitter' inserted inside 'emed' is 'EMBITTERED'.

'to become' is the link.