ad hoc ad hoc /ˈæd ˈhɒk/

adjective

1. For or concerned with one specific purpose  ( ad hoc )
   for or concerned with one specific purpose
    A coordinated policy instead of ad hoc decisions
   a coordinated policy instead of ad hoc decisions
   
2. Often improvised or impromptu  ( ad hoc )
   often improvised or impromptu
    An ad hoc committee meeting
   an ad hoc committee meeting
   

adverb

1. () For one specific case  ( ad hoc )
   for one specific case
    They were appointed ad hoc
   they were appointed ad hoc