Detempering
In regular temperament theory, detempering is the process of taking a tempered pitch system and replacing each of its pitches with a nearby JI pitch. Specifically, a detempered scale or a detemperament has each pitch of a tempered scale (according to a fixed regular temperament) replaced with one JI interpretation of the pitch under the temperament map. Ideally the resultant JI pitch system will have low prime limit and a compact lattice.
It is a distinct concept from a quasi-equal rational tuning, or neji, the main difference being that a neji replaces an equal temperament's pitches with pitches from a single harmonic series.