Learner's definition of LOIN
an area on the back of an animal's body near the tail
meat from this area
the area of a person's body that includes the sexual organs
◊ Your child or children can be referred to as the fruit of your loins. A child can be described as springing/coming from the loins of his or her parents. These phrases are usually used in a humorous way.
gird (up) your loins
to prepare yourself for a fight or for some difficult task