subfamily
Biological taxonomy term; a rank between family and genus.
ネコ科はネコ亜科とヒョウ亜科に分けられる。
The cat family is divided into the feline subfamily and the pantherine subfamily.
The cat belongs to the subfamily Felinae.
属 is the taxonomic rank 'genus', one level below 亜科 (subfamily), so the two are easily mixed up when discussing biological classification.
From 亜 (a, 'sub-') + 科 (ka, 'family'). A straightforward compound used in biological classification.