Occuring at times, but not constant, regular, or systematic; made or happening as opportunity requires or admits; casual; incidental; as, occasional remarks, or efforts.

under California law describes the frequency of a pain as occurring 25% of the time; of "occasional," "intermittent," "frequent," and "constant."

occurring from time to time; "took an occasional glass of wine"

Afflicting us with greater or less frequency. That, however, is not the sense in which the word is used in the phrase "occasional verses," which are verses written for an "occasion," such as an anniversary, a celebration or other event. True, they afflict us a little worse than other sorts of verse, but their name has no reference to irregular recurrence.

occurring or appearing at usually irregular intervals; "episodic in his affections"; "occasional headaches"

occurring at irregular intervals with a time lapse necessary to suit the purpose

Of or pertaining to an occasion or to occasions; intended for a specific occasion; for use only when needed, and not regularly.

A small number of characteristics that are arranged and somewhat diversely within the panel face.

Produced by accident; as, the occasional origin of a thing.

Designed or constructed to be used as the occasion demands. Multi-purpose.