Go off Romeo over time (3)
I believe the answer is:
rot
'go off' is the definition.
(I've seen this before)
'romeo over time' is the wordplay.
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'over' becomes 'o' (cricket abbreviation).
'time' becomes 't' (abbreviation).
'r'+'o'+'t'='ROT'
(Other definitions for rot that I've seen before include "Deterioration" , "Drivel" , "Collapse" , "Cobblers" , "Balderdash" .)