Flustered state following drink (4)
I believe the answer is:
flap
'flustered state' is the definition.
'flap' can be an answer for 'state' (I have seen 'State of panic' mean 'flap' so perhaps 'state' could also mean 'flap'). I'm not certain of the 'flustered' bit.
'following drink' is the wordplay.
'following' becomes 'f' (used when citing page numbers etc).
'drink' becomes 'lap' (lap can mean to drink).
'f'+'lap'='FLAP'
Can you help me to learn more?
(Other definitions for flap that I've seen before include "Panic; fold" , "Moving surface on wing" , "Tab - tizzy - move wings" , "State of agitation" , "Wave up and down - panic" .)