husband

(おっと) Husband
 
(だんな) Husband
 
Both words mean “husband” and both are used on formal as well as informal occasions. But 夫 is used in documents, while 旦那 is more used in conversation. The female equivalent of 夫 is 妻 (つま). The female equivalent of 旦那さん is 奥さん (おくさん).