| Trophic level | (Environmental Engineering) A level in the food chain. The first trophic level consists of the primary producers, autotrophs. The second trophic level is vegetarians which consume autotrophic organisms. |
| Troposphere | (Environmental Engineering) The lower atmosphere, from the earth's surface to approximately 12 km. This portion of the earth's atmosphere contains about 95 percent of the atmospheric gases. The temperature gradually declines through this region. |
| Ultimate disposal | (Environmental Engineering) The process of returning residuals back to the environment in a form which will have the minimal or reduced negative environmental impacts. |
| Waste minimization | (Environmental Engineering) The elimination or reduction of a waste prior to its generation. This is accomplished by process changes rather than waste treatment methods. |
| Abstraction - | (Software Engineering) (1) the level of technical detail of some representation of software; (2) a cohesive model of data or an algorithmic procedureAction (also called Software engineering action) - |
| Agile development (also referred to as agile process model) - | (Software Engineering) an adapted version of software engineering that emphasizes customer communication, incremental software delivery, informal methods and work products, and highly motivated teams. |
| Aspect-oriented development - | (Software Engineering) a development approach that emphasizes "concerns" (also called "aspectual requirements" that incorporate features, functions and information content) that cut across multiple system functions |
| Automated estimation tools - | (Software Engineering) tools that help in estimating project cost or effort |
| Baseline - | (Software Engineering) a point at which some deliverable produced during the software engineering process is put under formal change contro |
| Basis path testing - | (Software Engineering) a white box test case design technique that used the algorithmic flow of the program to design tests |