changing (one's job, loyalties, stance, etc.); switching over
changing quarters (of a geisha, prostitute, etc.)
彼は野党から与党へ鞍替えした。
He switched from the opposition to the ruling party.
鞍替えの噂が政界を騒がせている。
Rumors of party-switching are causing a stir in politics.
職業の鞍替えを決意して新たな道へ進んだ。
He decided to change careers and embarked on a new path.