First character has a record laugh (5)
I believe the answer is:
alpha
'first' is the definition.
(thesaurus)
'character has a record laugh' is the wordplay.
'character' becomes 'a'.
'has' is a charade indicator (letters next to each other).
'a record' becomes 'L-P' (abbreviation for long play record).
'laugh' becomes 'ha'.
'a'+'lp'+'ha'='ALPHA'
(Other definitions for alpha that I've seen before include "leader in Athens, originally" , "Brightest star" , "Foremost" , "Foreign character" , "letter opener" .)