Russell accepts an amount, on reflection, that'd make you laugh (5)
I believe the answer is:
amuse
'that'd make you laugh' is the definition.
I can't tell whether this definition defines the answer.
'russell accepts an amount on reflection' is the wordplay.
'russell' becomes 'ae' (I've seen this in other clues).
'accepts' means one lot of letters goes inside another.
'an amount' becomes 'sum' ('sum' can be a synonym of 'amount').
'on reflection' says the letters should be written in reverse.
'sum' backwards is 'mus'.
'ae' placed around 'mus' is 'AMUSE'.
Can you help me to learn more?
(Other definitions for amuse that I've seen before include "Enliven" , "Tickle" , "Beguile" , "Keep occupied" , "Reflect" .)