occasional

/ə-ˈkā-zh(ə-)nəl/

Middle English occasyonal "occurring at intervals," borrowed from Medieval Latin occāsiōnālis "opportune, incidental," from occāsiōn-, occāsiō + Latin -ālis

adjective

  1. of or relating to a particular occasion

  2. created for a particular occasion

  3. acting as the occasion or contributing cause of something

a budget able to meet occasional demands as well as regular ones

occasional verse