A companion or partner with whom one shares life; often refers to a spouse or long-term partner (a slightly formal term).
人生の伴侶を見つけたいと彼は言った。
He said he wanted to find a life partner.
彼女は良い伴侶を得て幸せに暮らしている。
She found a good partner and lives happily.
伴侶として互いに尊重し合うことが大切だ。
As partners, it's important to respect each other.