The business guy was convincing (6)
I believe the answer is:
cogent
'convincing' is the definition.
(similar in meaning)
'the business guy' is the wordplay.
'the business' becomes 'co' (short for company).
'guy' becomes 'gent' (I've seen this in another clue).
'co'+'gent'='COGENT'
'was' is the link.
(Other definitions for cogent that I've seen before include "Compelling or convincing" , "Well argued, compelling" , "Convincing, persuasive" , "Forceful - persuasive" , "'Powerfully persuasive, argument say (6)'" .)