億
オク, お

hundred million, 10**8

JLPT2 G4 S15 F716

As per 意# (contained in the heart). *One hundred million* is a borrowed meaning. Here, 人 has no semantic function, being used simply to create a derivative character conveying meanings that dropped from the original one (although in this case too the original sense eventually changed).

[Full Kanji Etymology List]