Bowled each length initially - a sound measure (3)
I believe the answer is:
bel
'a sound measure' is the definition.
(I've seen this in another clue)
'bowled each length initially' is the wordplay.
'initially' says to take the initial letters.
The initial letters of 'bowled each length' is 'BEL'.
(Other definitions for bel that I've seen before include "Some noise" , "Unit relating to sound intensity" , "Babylonian god" , "starts apocryphal work" , "Unit of volume" .)