It has been considered polite to call somebody else’s husband ご主人（ごしゅじん）and your own husband 主人（しゅじん）but the word 主人（しゅじん）originally means a “master” so many women these days start using the word 夫（おっと） for their own husband.

The word 囚人（しゅうじん） is also old-fashioned.  Newspapers usually use the word 受刑者（じゅけいしゃ）and  prisoners of war are usually called 捕虜（ほりょ）. 

しゅじん

しゅうじん