Swift pint at end of esplanade (6)
I believe the answer is:
prompt
'swift' is the definition.
(thesaurus)
'pint at end of esplanade' is the wordplay.
'pint' becomes 'pt' (abbreviation).
'at end of' is a charade indicator (letters next to each other) (some letters go at the end of others).
'esplanade' becomes 'prom' (I've seen this before).
'pt' put after 'prom' is 'PROMPT'.
(Other definitions for prompt that I've seen before include "Cause, bring about" , "Cause; on time" , "Cue given to a performer" , "Encourage" , "Remind (actor) of lines" .)