| loss of head | การสูญเสียความดันน้ำตามระยะทางการไหล |
| louver | บานเกล็ด |
| lower chord | ขื่อ |
| low-heat portland cement | ปูนซีเมนต์ปอร์ตแลนด์ความร้อนต่ำ |
| lurch | เอียง, เบน |
| Linear: | (english) A structure is said to behave linearly when its the deformation response is directly proportional to the loading (i.e. doubling the load doubles the displacement response). For a material, linear means that the stress is directly proportional to the strain. |
| Line of Action: | (english) The line of action of a force is the infinite line defined by extending along the direction of the force from the point where the force acts. |
| Linear Elastic: | (english) A force-displacement relationship which is both linear and elastic. For a structure, this means the deformation is proportional to the loading, and deformations disappear on unloading. For a material, the concept is the same except strain substitutes for deformation, and stress substitutes for load. |
| Load: | (english) An external force. The term load is sometimes used to describe more general actions such as temperature differentials or movements such as foundation settlements. |
| Landfill | (Environmental Engineering) A legal and controlled area for the placement of wastes into the ground. |