One of a matched pair of things
A husband or wife
One who shares interests or activities with another
A person whom one knows well, likes, and trusts
To join or be joined in marriage
To engage in sexual relations with
One of a pair
A marriage partner
A naval officer
She's your mate and my sister.
Carmen had been his soul mate for a long time.
A human mate and so soon after he's taken command.
A bad deal by a deity or its mate will ruin the universe.
"His mate," Xander said with his slow smile.