The etymological relation of PAT *ħʷǝ and PAK *χʷǝ is quite transparent (cf., e.g., the same combination of meanings in the reflexes of the related PL *χ:Iol), and the attempts to relate PAK *χʷǝ to the verb *χʷǝ- 'to ripen, to become' (Яковлев 1948, 180, Shagirov 1977,2,112) are obviously folk-etymological. Ub. χʷǝ (compared with PAK *χʷǝ by Abdokov 1973, 73) may be an Ad. loan (which is the idea of T. Esenč, see Vogt 1963, 209, and of Shagirov 1977,2,112), but may well also be genuinely related (the phonetic correspondences are quite regular).