寝返 ねがえ
negaeri

Noun
Suru Verb

1. turning over in bed; rolling over; tossing and turning

Intransitive
Related to 寝返りを打つ
彼女 かのじょがベッドで寝返 ねがえりばかりうっている。
kanojoga beddode negaeribakari utte iru.
She is tossing and turning in bed.
Noun
Suru Verb

2. betrayal; double-crossing

こいつ、さっきまで おれ相棒 あいぼうだったのに、もう寝返 ねがえりやがった。
koitsu sakkimade oreno aibōdattanoni mō negaeriyagatta.
This rat, up until just now he was my partner and now he's gone and turned on me.