German beer wasted on bird (5)
I believe the answer is:
grebe
'bird' is the definition.
(type of bird)
'german beer wasted on' is the wordplay.
'german' becomes 'g' (abbreviation).
'wasted' indicates anagramming the letters.
'on' means one lot of letters go next to another.
'beer' is an anagram of 'rebe'.
'g'+'rebe'='GREBE'
(Other definitions for grebe that I've seen before include "Aquatic bird that builds floating nests" , "I'll dive in" , "Crested water-bird" , "Flier" , "Diving waterbird" .)