subgroup

/ˈsəbˌgrup/

a distinct and often subordinate group within a group

中文释义：子群；亚群

The researchers identified a subgroup of patients who responded well to the treatment.

研究人员识别出一组对治疗反应良好的患者亚群。

Within the bird species, a distinct subgroup migrates south every winter.

在这种鸟类中，一个独特的亚群每年冬天向南迁徙。