noun, noun or participle which takes 'suru'
satisfaction; contentment
Refers to a state of being satisfied or content, often with a nuance of heartfelt acceptance. Can be used as a noun or with する to mean 'to be satisfied'.
彼はその結果に甘心した。
He was satisfied with the result.
甘心の笑みを浮かべる。
To wear a smile of satisfaction.