on an ad hoc basis collocation If you do something on an ad hoc basis, you do it only when you need to and in a way that is not planned before it happens: We deal with problems on an ad hoc basis. Our finance committee is a standing committee, but we only convene our conference committee on an ad hoc basis. See
ad hoc
basis We allow our employees to work from home on an ad hoc basis rather than as a matter of course. The regulations are likely to be enacted on an ad hoc basis. Spending money on an ad hoc basis will not permanently solve the problem.