Fetching details from the dictionary...
father-in-law
foster father
stepfather
週末に義父と釣りに出かけた。
I went fishing with my father-in-law on the weekend.
義父は穏やかな性格の人だ。
My father-in-law is a gentle person.
来月の連休に義父の家を訪ねる予定だ。
I plan to visit my father-in-law's house during next month's holidays.