くよくよ
kuyokuyo

Suru Verb

1. to fret (over); to brood (about); to mope; to worry

Onomatopoeia
To-Adverb

2. worriedly; (fretting) constantly; (worrying) over this and that; (obsessing) to no end

Onomatopoeia
かれ過去 かこ失敗 しっぱい ことをくよくよ おもっている。
karewa kakono shippaino kotō kuyokuyo omotte iru.
He dwells on his past failures.
Other forms: