| Translation: | (english) Motion of an object where the path of every point is a straight line. |
| Vector: | (english) A mathematical entity having a magnitude and a direction in space. |
| Velocity: | (english) A vector quantity equal to the rate that position changes with time. |
| Yield stress: | (english) A material loaded beyond its yield stress, no longer exhibits linear elastic behavior. Metals, particularly mild steel, generally have a very well defined yield stress compared to other materials. Yield stress is sometimes called yield strength. |
| Advanced wastewater treatment | (Environmental Engineering) The removal of any dissolved or suspended contaminants beyond secondary treatment, often this is the removal of the nutrients nitrogen and/or phosphorus. |
| Anoxic process | (Environmental Engineering) A process which occurs only at very low levels of molecular oxygen or in the absence of molecular oxygen. |
| Aromatic | (Environmental Engineering) A form of bonding in which ring compounds share electrons over more than two atoms. The electrons are delocalized. This leads to unusual ring stability. |
| Autotrophs | (Environmental Engineering) A group of organisms capable of obtaining carbon for synthesis from inorganic carbon sources such as carbon dioxide and its dissolved species (the carbonates). This group includes plants and algae. |
| Bacteria | (Environmental Engineering) One celled microorganisms which do not have a nuclear membrane. |
| Baghouse filter | (Environmental Engineering) A fabric filter device used to remove particulate air pollutants. |