I don't laugh a long time after everyone else (7)
I believe the answer is:
agelast
'i don't laugh a long' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'time after everyone else' is the wordplay.
'time' becomes 'age' (an age is a period of time).
'after everyone else' becomes 'last' (I've seen this in another clue).
'age'+'last'='AGELAST'
Can you help me to learn more?
(Other definitions for agelast that I've seen before include "one impervious to cracks?" , "I won't laugh" , "such as Buster Keaton" .)