Meaning & readings

hundred million, 10**8

On’yomi オク
Nanori

Origin

The character combines a person classifier on the left with , which provides a sound hint for how to pronounce it (roughly "o" sound). In Chinese, this character was created to represent the enormous number hundred million by pairing a human-related radical with a phonetic component. The person classifier likely suggests the idea of counting or reckoning something so vast that only humans would need to track it, while the right side tells you how to say the word aloud. Over time, the character became the standard way to write this large numerical unit in both Chinese and Japanese.

AI-generated (claude-haiku-4-5), not yet reviewed. Formation type (automated guess): Phono-semantic (meaning + sound hint).

15 strokes

Components

  • radical left
  • sound hint right

A sound hint component points at the character’s pronunciation, not its meaning — don’t read a meaning into it.

Common words

  • 一億 いちおく 100,000,000; one hundred million
  • 十億 じゅうおく 1,000,000,000; billion
  • 数億年 すうおくねん several hundred million years
  • 100億 ひゃくおく 10,000,000,000; ten billion

Reference

Strokes
15
Kangxi radical
9
Grade
Grade 4 (Kyōiku)
Frequency rank
#716 (newspapers)
Former JLPT
level 2
Unicode
U+05104