occasional

Etymology

occasion + -al

adj

1. Occurring or appearing irregularly from time to time, but not often.
   He was mostly solitary, but enjoyed the occasional visitor.
   He took an occasional glass of wine.
   The highway to the East Coast which ran through the borough of Ebbfield had always been a main road and even now, despite the vast garages, the pylons and the gaily painted factory glasshouses which had sprung up beside it, there still remained an occasional trace of past cultures. 1963, Margery Allingham, chapter 7, in The China Governess
   But the truth is that plenty of artists from other countries make work that's bold, naughty or nasty, without getting more than a very occasional headline. April 17, 2003, Blake Gopnik, “Art That Advertises Itself; Saatchi's Ornate New Gallery Pits Young British Artists Against the Establishment”, in Washington Post
2. Created for a specific occasion.
   Elgar's music was not created to be occasional music for high-school graduations.
3. Intended for use as the occasion requires.
   What your living room needs are some occasional chairs.
4. Acting in the indicated role from time to time.
   He is an occasional writer of letters to the editor.

noun

1. A person who does something only occasionally.