Blacklist young lad on bed, it’s said (7)
I believe the answer is:
boycott
'blacklist' is the definition.
(thesaurus)
'young lad on bed it's said' is the wordplay.
'young lad' becomes 'boy' (lad can mean informally mean a boy).
'on' says to put letters next to each other.
'bed' becomes 'cot' (cot is a kind of bed).
'it's said' becomes 't' (I've seen this in other clues).
'boy'+'cot'+'t'='BOYCOTT'
(Other definitions for boycott that I've seen before include "send to Coventry" , "Refuse to deal with (someone) as a protest" , "Punitive ban" , "Refuse to buy or handle goods" , "Refuse to handle or deal with" .)