Clear run into bay (6)
I believe the answer is:
bright
'clear' is the definition.
(as in sunny weather)
'run into bay' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'into' means one lot of letters goes inside another.
'bay' becomes 'bight' (bight is a kind of bay).
'r' put into 'bight' is 'BRIGHT'.
(Other definitions for bright that I've seen before include "Sparkling" , "Jolly" , "Vivid; cheerfully lively" , "full of promise" , "Clever - shining - sunny" .)