妥
ダ, やす

gentle, peace, depravity

JLPT1 G7 S7 F1102

A variant form of 垂 hang (compare 朶, another variant of 垂 also composed of etymologically unrelated elements), with the specific nuance "hang in the appropriate way/place" → *contentment* (← be satisfactory ← be appropriate) → *calm*; *peace*.

[Full Kanji Etymology List]