unretained

Unretained is an English adjective formed by adding the prefix un- to retained. It means not retained; not kept or held in place. The term is typically used in technical or academic writing to describe something that fails to be preserved, stored, remembered, or kept within a system, process, or dataset. It is most often used as a contrast to retained.

In memory research and education, unretained information refers to material that learners do not remember after an interval. Studies may distinguish retained versus unretained items to assess learning or forgetting curves, often reporting retention rates as a function of time, task, or condition.

In chemistry and analytical techniques, unretained describes substances that do not interact significantly with a stationary phase and therefore pass through a chromatographic system with little or no retardation. Such compounds elute near the solvent front, in contrast to retained substances that are slowed by adsorption, partitioning, or other interactions.

In linguistics and historical linguistics, unretained can describe features or sounds that are not carried forward into later stages, languages, or variants. More generally, the word is used wherever a subject is described as not being preserved, kept, or maintained within a process, record, or dataset.