Spent erratically, concealing record (5)
I believe the answer is:
enter
'record' is the definition.
(enter can mean to enter into a record)
'spent erratically concealing' is the wordplay.
'concealing' says the answer is hidden in the clue.
'ENTER' is hidden in the letters of 'spent erratically'.
(Other definitions for enter that I've seen before include "Enroll, sign up" , "put in for a race" , "Come/go in" , "Infiltrate" , "Break in" .)