a.

1. 偶爾的，非經常的
   She likes an occasional glass of wine.

   她喜歡偶爾喝杯酒。

   He pays me occasional visits.

   他偶爾來看我一次。

2. 特殊場合的，應景的[B]
   Occasional music was played at the graduation.

   畢業典禮上演奏了應景的音樂。

3. 臨時的
   Upon a little occasional table was a tray with breakfast things.

   在一張臨時用的小桌子上放著一個盛著早餐及餐具的盤子。

adj.

1. occurring infrequently or irregularly.
2. produced on or intended for particular occasions:
   occasional verse.