A word appearing as G. polodrin “mighty” in the Gnomish Lexicon of the 1910s, an adjective form of G. polod “power, might, authority” (GL/64). It had an archaic variant {poldurin >>} †polurin or polorin which was sometimes used as a sobriquet for Tulcus.
Neo-Sindarin: Since ᴹ√POL(OD) still had to do with “strength” in Tolkien’s later writings, I’d adapt this word as ᴺS. polodhren “mighty, ✱powerful” for purposes of Neo-Sindarin using the later Sindarin adjective -ren. Given the meanings of its base noun (including authority), I’d assume this adjective has a connotation of political power. I’d constrast it with S. belaith which I’d use for “mighty” in general (independent of authority).
An adjective appearing as G. {bald >>} bâl “worthy, important; great, mighty” in the Gnomish Lexicon of the 1910s based on the early root ᴱ√vḷd (GL/21).
Neo-Sindarin: For purposes of Neo-Sindarin, I would adapt this as ᴺS. ball “worthy, important” to be equivalent ᴱQ. valda, as originally suggested by Elaran in a 2018-08-03 post to the Vinyë Lambengolmor Discord Server (VLDS). I would not use this word for “great, might”, however.