千
セン, ち, かず, ゆき
thousand
JLPT5 G1 S3 F195
The relevant oracle bone form of this character is 人 person with a line drawn at the shin to indicate a person progressing in small increments through luxuriant vegetation (compare 年 and 延) → *one thousand* (← number reached by counting on and on). It is unclear whether it is 人 or the line element acting as the phonosemantic element.
[Full Kanji Etymology List]