Thanih Ras al Akab is Arabic for the second in the head of the eagle, from thani, second, ras, head, and uqab, eagle. It belongs to the same descriptive family as the tail-names of Aquila and shows the method of the older Arabic star nomenclature at its clearest: rather than giving each star an arbitrary proper name, the tradition named stars by their place in the figure and their order within that place, so that a catalogue entry is really a short sentence of position. Names of this length were commonly shortened or garbled in Latin transmission, and several familiar modern star names are the worn-down remains of such phrases. No traditional planetary nature is recorded for this star, and the astrological tradition attaches no meaning to it beyond its position in the constellation.
A name built this precisely, second, head, eagle, is functionally a coordinate rather than a proper name in the modern sense, and the habit of naming stars by their exact anatomical place in a figure, rather than giving each an independent word, is one of the clearest structural differences between the older Arabic descriptive layer and the later custom, more Latin and Renaissance in spirit, of giving a star a single fixed proper name regardless of its position. Names of exactly this kind are the staple of Richard Hinckley Allen's 1899 Star Names, the standard English reference for this whole layer of the catalogue's nomenclature.