. Lat, . T?bus, *. Proto-romance, ~. *. , <. Com et al., *tú?o-(Meyer-Lübke, 1935:746) reflecting a source word *tuPoderived from zero-grade PIE *d h úb h -o-[m.] 'ravine' from PIE *d h ub h -ó-'deep.' This PIE formation would have been inherited as Com. It. **?ú?o-and would appear as Lat. **f?bus. 5 It is generally accepted that Gr. ?????? is akin to the Myc. Gr. ku-su-to-ro-qa 'global sum', probably for *???-????????( ????????(cf. Gr. ???????? 'density, condensation, gathering, group'). Therefore, an etymology for Gr. ?????? based on the PIE root *trep-'turn' is unlikely, p.603, 2001.