yṇtṇ

root. *(en)large, increase

The unglossed root ᴱ√DẎṆTṆ appeared in the Qenya Lexicon with derivatives like ᴱQ. yanta “large” and ᴱQ. yanta- “enlarge, increase, add to”; Tolkien also wrote and then erased a note saying “or ẎṆTṆ” (QL/106). In the contemporaneous Gnomish Lexicon Tolkien gave primitive yṇt as the basis for words like G. gant “larger, greater, more; (lit.) increased” and G. gantha “more” (GL/37). The superlative forms ᴱN. diant “most” and ᴱN. -iant from the Early Noldorin Grammar from the 1920s were probably related. I think it is worth positing a Neo-Root √GYANTA “(en)large, increase” to salvage some of these early words.