妻(つま)

妻(つま) is the neutral, standard term for 'wife,' used in both spoken and written Japanese. The male equivalent is 夫(おっと).

OWN VS. OTHERS' WIFE:
妻 can refer to one's own wife or, in formal writing, to a third party's wife. In spoken language when referring to someone else's wife, 奥(おく)さん (respectful) is more natural than 妻. For one's own wife, alternatives include 家内(かない) (old-fashioned humble term, literally 'inside the house') and 嫁(よめ) (casual, common in Kansai and younger speech). 妻 itself strikes a neutral, modern tone and is the standard choice in official documents (戸籍, legal contracts, etc.).