One's spouse's father; father-in-law (by marriage).
結婚式で義父が新郎の紹介をした。
At the wedding, the father-in-law introduced the groom.
私の義父は趣味で家庭菜園をしている。
My father-in-law has a home vegetable garden as a hobby.
義父に挨拶をしてから席に着いた。
I greeted my father-in-law and then took a seat.
A man who acted as a father by raising or caring for someone but is not the biological father; a foster/adoptive father.
彼は幼い頃、義父に育てられたため本当の父親のことをあまり知らない。
He was raised by his foster father when he was young, so he doesn't know much about his biological father.
学校の行事に義父が来てくれて嬉しかった。
I was happy that my foster father came to the school event.
義父は私に釣りを教えてくれた大切な存在だ。
My foster father is an important person who taught me how to fish.
A father in a blended family formed by remarriage; a stepfather (a man who became a parent to a child from a previous marriage).
母が再婚して、義父ができたが最初は慣れなかった。
When my mother remarried I got a stepfather, but I didn't get used to him at first.
義父は私のことを自分の子どものように扱ってくれた。
My stepfather treated me like his own child.
義父と休日に映画を観に行った。
I went to see a movie with my stepfather on a day off.