Occasional
Occasional (ok*kā"zhun*al) , adjective
[Compare French occasionnel.]
1.
Occurring at times, but not constant, regular, or systematic; made or happening as opportunity requires or admits; casual; incidental; as, occasional remarks, or efforts.
The... occasional writing of the present times.
2.
Produced by accident; as, the occasional origin of a thing. [Obsolete] — Sir T. Browne
3.
Of or pertaining to an occasion or to occasions; intended for a specific occasion; for use only when needed, and not regularly.
Collocations (1)
Occasional cause (Metaphysics) , some circumstance preceding an effect which, without being the real cause, becomes the occasion of the action of the efficient cause; thus, the act of touching gunpowder with fire is the occasional, but not the efficient, cause of an explosion.