Does anyone know what tree produces a fruit about the size of a lemon or lime?

Question

The fruit unripened is green with a very hard skin. It's not a lime because it has a pit, which I found when I cut it open.The texture of the fruit is similar to an avocado. It has an unpleasant smell.

Answer 1

horse apple? those r usually very hard and large and green when ripe but are also green unripped. i dont know if people eat them and they do smell and taste bad.