Ancient American good to meet news boss (4)
I believe the answer is:
aged
'ancient' is the definition.
(thesaurus)
'american good to meet news boss' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'good' becomes 'g' (abbreviation).
'to meet' says to put letters next to each other.
'news boss' becomes 'ed' (I've seen this in other clues).
'a'+'g'+'ed'='AGED'
(Other definitions for aged that I've seen before include "Matured like wine in wood" , "Geriatric" , "Old or ancient" , "Long in the tooth" , "well over the hill" .)