anarthrou

a. [ Gr. '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. [ 1913 Webster ]

2. (Zool.) Without joints, or having the joints indistinct, as some insects. [ 1913 Webster ]