ad hoc

Adj.	1.	ad hoc - often improvised or impromptu; "an ad hoc committee meeting"
	2.	ad hoc - for or concerned with one specific purpose; "a coordinated policy instead of ad hoc decisions"
Adv.	1.	ad hoc - for one specific case; "they were appointed ad hoc"

ad hoc - Contrived purely for the purpose in hand rather than planned carefully in advance. E.g. "We didn't know what to do about the sausage rolls, so we set up an ad-hoc committee".