#3420 PTB *k-tu-k PENIS |
This root, which has allofams both with and without a final velar stop, is found in several different subgroups of TB: NE Indian Areal Group, Himalayish, Asakian, Qiangic (including Xixia), and Baic. It has so far not been discovered in Lolo-Burmese or Karenic.
This root resembles #3423 PTB *tsu PENIS. The possibility that these two etyma might be one and the same is reinforced by the natural tendency of /t/ to become affricated before /u/, as witnessed by Japanese, where /tu/ is realized as [tsɯ].
This etymon also bears a perhaps accidental resemblance to #661 PTB *s‑tu VAGINA / VULVA.
An apparently prefixal k‑ is attested in Kham and Spiti. Cf. also the Tangut binome khǐu̱ thu.