人差指
ひとさしゆび · hitosashiyubi · JLPT N2 · noun
index
👆 人 (person) + 差す (point at) + 指 (finger) = finger for pointing at people
差す means to point at or thrust toward. The word names the finger you use to point at a person. Plain 指 means any finger, and 人差し指 narrows it to the pointing one.
人 — pictograph of a standing person
人 is a pictograph showing a person viewed from the side, with two strokes representing the legs and torso of a standing human. In oracle bone script it clearly depicted a figure leaning slightly forward. The meaning has remained 'person' or 'human' throughout its history.
差 — 垂 (drooping) + 工 (work/tool)
Originally depicted a hand reaching down to grasp grain stalks of uneven length, suggesting discrepancy or unevenness. From this came the meaning 'difference' or 'to differ.' The reading chā specifically carries the sense of disparity, while other readings developed meanings like 'to dispatch' (chāi) and 'poor/lacking' (chà).
指 — hand radical 扌 + 旨 (zhǐ, phonetic)
指 is a semantic-phonetic compound. The hand radical 扌 gives the meaning — something done with the hand, namely pointing with a finger. 旨 supplies the sound 'zhǐ'. From 'finger' it naturally extended to the verb 'to point' and figurative senses like 'to indicate' or 'to refer to'.