Effect of sun cheers by noon (3)
I believe the answer is:
tan
'effect of sun' is the definition.
(as in a sun tan)
'cheers by noon' is the wordplay.
'cheers' becomes 'ta' (I've seen this in other clues).
'by' says to put letters next to each other.
'noon' becomes 'n' (**).
'ta'+'n'='TAN'
(Other definitions for tan that I've seen before include "Catch the sun" , "Yellowish brown" , "Make black and blue" , "Sun-kissed" , "Lie in sun" .)