The original meaning is present already in early inscriptions (see
Schüssler 203); in the classics, however, the character is used only as a loan for a homonymous *kā 'for a time, meanwhile'.

    The OC *kā 'father's sister' seems to have no connections in Sino-Tibetan languages. It resembles the PA kinship term *äk`a, but the resemblance may be purely coincidental ("children's word").

    The etymology of *kā 'meanwhile, for a time' is also not quite clear. The closest existing parallel is Tib. ãga 'some, something, somebody', used also in the meaning 'sometimes' (but considered in this meaning to be a contraction of lan-ãga). It seems probable that both the Chinese and the Tibetan words are derived from the common ST demonstrative stem *kă (see under 其), but the details are yet to be found out.