The name appears in Herodotus (Hdt 7, 109), Strabo (Strab. 7, fr. 47), Pliny the Elder (Plin. 4, 42), Ptolemy (Ptol. 3, 11, 5) and Aelian (Ael. De nat. anim. 15, 25).

The name was defined as Thracian by D. Detschew, who derived it from ie *bheidh- and believes that the same root is found not only in the name of the lake and the tribe, but also in the second component – βιστας / – βειστας in several Thracian personal names, and corresponds to the Ancient Greek πιστός.

Georgiev followed this etymology for the component part of personal names, but he does not mention the name of the lake and the tribe. D. Detschew’s assumption that the names of the tribe and the lake have the same root as the component – βιστας (there is also a personal name Βιστης, Βιστα) seems convincing. The etymology and comparison with the Greek word πιστός remain uncertain.