An·ar'throus adjective [ Greek 'a`narqros without joints, without the article; 'an priv. + 'a`rqron joint, the article.] 1. (Gr. Gram.) Used without the article; as, an anarthrous substantive. 2. (Zoology) Without joints, or havin... Found on http://www.encyclo.co.uk/webster/A/78