sporadic

1. ADJ Sporadic occurrences of something happen at irregular intervals. 零星的

...a year of sporadic fighting in the north of the country. …该国北部有零星战火的一年。

2. sporadicallyADV 零星地[ADV with v]

The distant thunder from the coast continued sporadically. 远处海岸仍然零星地传来雷声。