Offender caught lip in a laptop (8)
I believe the answer is:
criminal
'offender' is the definition.
(I know that offender can be written as criminal)
'caught lip in a laptop' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'lip' becomes 'rim' (synonyms).
'laptop' becomes 'l' (top of the word 'lap').
'c'+'rim'+'in'+'a'+'l'='CRIMINAL'
(Other definitions for criminal that I've seen before include "An habitual breaker of the law" , "Offender" , "A bad hat" , "Violating the law" , "Deplorable, shocking" .)