An‐ar″throus (�), a. [Gr. ἄναρθροσ without joints, without the article; αν̓ priv. + ἄρθρον joint, the article.] 1. (Gr. Gram.) Used without the article; as, an anarthrous substantive.
2. (Zoöl.) Without joints, or having the joints indistinct, as some insects.