Bond following mostly American (5)
I believe the answer is:
nexus
'bond' is the definition.
(thesaurus)
'following mostly american' is the wordplay.
'following' becomes 'next' ('next' can be a synonym of 'following').
'mostly' means to remove the last letter.
'american' becomes 'us'.
'next' with its last letter taken off is 'nex'.
'nex'+'us'='NEXUS'
(Other definitions for nexus that I've seen before include "Connection; focal point" , "Connecting bond" , "Connected series; central point" , "Focal point; link" , "Unsex in connected group or series" .)