Rotten piece of job advice (3)
I believe the answer is:
bad
'rotten' is the definition.
(similar in meaning)
'piece of job advice' is the wordplay.
'piece of' indicates a hidden word.
'BAD' can be found hidden inside 'job advice'.
(Other definitions for bad that I've seen before include "SECOND HALF OF 16" , "Spoiled or evil" , "(Of food) decayed" , "Substandard" , "Severe; of low standard" .)