Of occasion; incidental; hence, occurring from time to time, but without regularity or system; made, happening, or recurring as opportunity requires or admits: as, an occasional smile; an occasional fit of coughing.Called forth, produced, or used on some special occasion or event; suited for a particular occasion: as, an occasional discourse.That serves as or constitutes the occasion or indirect cause; causal.n. A production caused by or adapted to some special occurrence, or the circumstances of the moment; an extemporaneous composition.