borrowed from Medieval Latin, borrowed from Arabic al-dabarān, probably a name for the Hyades star cluster
Arabic usage is not uniform in regard to whether al-dabarān is to be interpreted as the star α Tauri, or the entire Hyades star cluster, though the phrase in the Almagest, translating Ptolemy's Greek text, suggests the latter. Arabic authors took dabarān as a derivative of the root d-b-r, with meanings related to "back" (hence dabarī "trailing behind"), on the grounds that the Hyades, along with α Tauri, trailed behind or followed the Pleiades. This has the appearance of an after-the-fact etymology, however, and dabarān may be a pre-Islamic name for the cluster, of unknown origin. See Paul Kunitzsch, Arabische Sternnamen in Europa (Wiesbaden, 1959) pp. 109-10.