Na't: the description
نَعْتna't - description
Na't is the describing word in a descriptive phrase. ILMHUB prioritises na't over sifah.
Simple explanation
نَعْت (na't) is the word that describes the مَنْعُوت (man'ut).
ILMHUB uses na't as the primary term, while noting that some books may also use sifah.