ニン, まか.せる, まか.す, さ, とう, ひで
responsibility, duty, term, entrust to, appoint
JLPT3 G5 S6 F217
As per 壬# (encompass) + 人 person (→ human agency) → encompass/bear *responsibility* → *duty* → *undertake* (← undertake a duty/responsibility) → *entrust*; *leave* (up to another) (← entrust/leave up to another a duty or responsibility) → *leave to chance*; *endure* (← endure a duty).
[Full Kanji Etymology List]