noun
sac spider (family Clubionidae)
Refers to any spider of the family Clubionidae. A technical zoological term; in everyday contexts, people may simply say クモ.
フクログモは、葉の裏に袋状の巣を作ることで知られている。
Sac spiders are known for making sac-like nests on the undersides of leaves.
Specifically refers to the species Atypus karschi, a type of trapdoor spider. Cross-referenced with ジグモ, which is another name for a similar spider. This sense is distinct from the general sac spider meaning.
See also: ジグモ
ジグモとフクログモは近縁だが、別の種類として扱われることが多い。
Jigumo and fukurogumo are closely related, but are often treated as separate species.
ジグモ refers to a similar mygalomorph spider (often Atypus karschi as well, or related species). フクログモ can be used for the same species or for sac spiders in general, while ジグモ is more specifically a trapdoor spider.
Compound of 袋 (fukuro, 'bag, sack') and 蜘蛛 (kumo, 'spider'), referring to the sac-like nests built by these spiders. The exact historical derivation is uncertain, but the name is descriptive.