Refers to a man in the context of marriage, often from the perspective of his bride or her family. Can mean 'husband' or specifically 'groom' at a wedding.
My daughter's husband is a very kind person.
The groom is nervous at the wedding ceremony.
Used to refer to one's own son-in-law or someone else's son-in-law. The possessive 'one's' is implied by context; the word itself does not inherently mean 'my'.
He is my son-in-law.
I went fishing with my son-in-law.
He married into his wife's family and took her surname.
Since they had only a daughter, they decided to take in a son-in-law.
The company president decided to make his subordinate his son-in-law.
He became the company president's son-in-law.
elder sister's husband; brother-in-law
son-in-law
brother-in-law (husband of one's spouse's sister)
man who marries into his wife's family; adopted son-in-law
marrying into the bride's family; adoption by the bride's family
taking a husband for one's daughter; adopting a son-in-law
search for a husband for one's daughter; choosing a son-in-law
Rarely used kanji form.