It is mentioned by Pliny the Elder as Geodos. According to him, it has another name, Chrysorroas (Plin. NH 5, 148). The name appears as Γευδος in an inscription on coins from Nicaea, (Head 1887: 443), while in Nonnus is Γεῡδις (Nonn. Dion. 11, 37; 17, 35; 43, 417).

Tomaschek was the first to identify the name as Thracian, cautiously suggesting an etymology associated with the ancient Greek adjective χυδαῖος, from the verb χέω, ‘to pour out’. D. Detschev rejects this, as he believes it contradicts the satem nature of the Thracian language and suggests that the name may be an extension of i.e. *geu- ‘to wander, to meander’. His suggestion, however, contradicts his own thesis about the presence of consonant shifts in Thracian. Tomaschek’s etymology was also accepted by I. Russu.

Tishler considers the name to be of Greek origin, accepting as correct the reading Geodos in Pliny, i.e. Γέωδος < γεώδης ‘earthly,’ without mentioning the other two references. However, it is most likely that all three testimonies refer to the same river, since in all three it is a question of Bithynia, which explains why the reading Geudos seems certain (the spelling of the name on the coins should more accurately reflect the actual pronunciation). Therefore, the assumption of Greek origin, which is not very convincing anyway because of the semantics, is ruled out and the name must be regarded as Thracian. The idea of a dental extension of the base Γευ- is supported by the existence of a parallel – the resident name Γευπασηνος from the probable name of the settlement * Γευπασα in an inscription from the village of Lozen, Haskovo region (IGBulg. III 2, No. 1811), which can be regarded as a two-part compound Γευ-πασα.

The suggested etymologies are not probable.