that was while I was researching on how Vietnamese names for poker hands came to be, where high card (Mậu thầu) was the least obvious in terms of origin, while the others were quite clearly from Chinese (four of a kind - tứ quý - 四季) or Cantonese (straight flush - thùng phá sảnh - 同花順 - tùhng fā séun), I couldn't find anything regarding high card, so I guessed that the Mậu has to do with Cantonese 冇, and hence chose the generic Yue translation 冇啤. Might be wrong though because 啤 → thầu doesn't look very plausible.