一切經音義 38.5

38.5

拇指（上莫補反古今正字云足大指也從手母聲也）。

Thumb or big toe (拇指: the upper character has the fanqie [m- + -u] 莫補. The Gujin zhengzi states: ‘The big toe of the foot. It is classified under the “hand” radical with “mother” [母] as its phonetic component.’)