A word in Late Notes on Verb Structure (LVS) from 1969 glossed “press, thrust, force (in a given direction)” and derived from √NID “force, press(ure), thrust” (PE22/165). Tolkien further specified that “though applicable to the pressure of a person on others, by mind and ‘will’ as well as by physical strength, [nir-] could also be used of physical pressures exerted by inanimates”, and that this verb “was as in Q. used as ‘urge, press, force’ generally without limitation to operations of mind”, as opposed to Sindarin where nidh- was purely mental/social.
Neo-Quenya: Röandil suggested in the “Neologism of the Day” series on the Vinyë Lambengolmor Discord Server (VLDS) in 2023-03-30 that this verb might also have the sense “impose” when used with the pressured party in the allative, as in i eldar ninder i santie tenna “the elves imposed [pressed] the decision on them”.
nindë adj. "slender" (NIN-DI, pointing to a stem-form nindi-). Not to be confused with *nindë as the likely pa.t. of the verb nir-, q.v.