Sneer at some caffeineless coffee (5)
I believe the answer is:
scoff
'sneer at' is the definition.
(thesaurus)
'some caffeineless coffee' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'SCOFF' can be found hidden inside 'caffeineless coffee'.
(Other definitions for scoff that I've seen before include "food on offer" , "Mock" , "Greedily consume" , "Ridicule - guzzle" , "Speak scornfully; eat" .)