noun
preferred term
In computing, the term designated as the primary or recommended label for a concept, often in controlled vocabularies or thesauri.
このシソーラスでは、各概念に優先使用語が一つ割り当てられている。
In this thesaurus, each concept is assigned one preferred term.
非優先語 is a non-preferred term, often a synonym or variant that redirects to the preferred term.
Compound of 優先 (priority) + 使用 (use) + 語 (word). A straightforward modern technical term.