母ぼ指し対たい向こう性せい

also: おやゆびたいこうせい

ぼ

し

た

い

こ

う

せ

い

Meanings

1

opposable thumb; thumb opposition

Medical/anatomical term referring to the ability of the thumb to touch the fingertips, a key feature of primate hands.

た

重じゅう

要よう

な

特とく

徴ちょう

で

ある

。

The opposable thumb in humans is an important feature that enabled tool use.

母ぼ指し対たい向こう性せいの喪そう失しつは、日にち常じょう生せい活かつに大おおきな支し障しょうをきたす。

Loss of thumb opposition causes significant difficulty in daily life.

対たい向こう
Means 'opposition' or 'facing each other'; 母指対向性 specifically refers to the thumb's ability to oppose the other fingers.
母ぼ指し
Medical term for 'thumb'; 母指対向性 is the property of the thumb being opposable.

母指対向性
- ぼしたいこうせい
  Standard kanji spelling; 母指 is the common way to write 'thumb' in medical contexts.
- おやゆびたいこうせい
拇指対向性
- ぼしたいこうせい
  Alternate kanji spelling using 拇, which is also used in medical terminology but less common than 母指.
- おやゆびたいこうせい
おやゆびたいこうせい
Kun'yomi-based reading; rarely used in practice. The on'yomi reading ぼしたいこうせい is standard in medical contexts.

Compound of 母指 (ぼし, 'thumb') + 対向 (たいこう, 'opposition') + 性 (せい, 'property'). A modern medical coinage.

性せい