ad hoc

形容词 ad hoc:

1. often improvised or impromptu
2. for or concerned with one specific purpose

副词 ad hoc:

1. for one specific case

1. Points of policy are decided ad hoc.
   政策的条款是临时决定的。
2. Problems were solved on an ad hoc basis.
   做了一些变通问题便解决了。