The term "lime" can refer to several different things, depending on its context.
1) Lime is a tree that produces small, sweet fruit which is used in various food and drink preparations such as margaritas or key lime pie.
2) It may also refer to the green-skinned citrus fruit known as "lime," which has a tart flavor and is commonly used for its juice or zest in cooking, particularly in Mexican, Caribbean, and Southeast Asian cuisine.
3) In chemistry, lime refers to calcium oxide (CaO), a white crystalline solid that reacts with water to form quicklime (calcium hydroxide). Lime is used for various purposes such as in the manufacture of cement and as a soil conditioner.
4) In construction, lime refers to building materials made from lime or mortar mixed with sand and water, which hardens when exposed to air or water. This type of material has been used for centuries due to its durability, flexibility, and resistance to weather damage.