ADJ (形势所需而)临时安排的,特别的,专门的 An ad hoc activity or organization is done or formed only because a situation has made it necessary and is not planned in advance.
The Council meets on an ad hoc basis to discuss problems. 议会临时安排会议讨论问题。
...ad hoc committees to examine specific problems. 研究具体问题的专门委员会