This root and ones like it were the basis for Elvish “man” words for much of Tolkien’s life. The earliest form of this root was ᴱ√NERE with derivatives like ᴱQ. ner “man, husband” and ᴱQ. nertu “strength” (QL/65). The latter had a cognate G. nert in contemporaneous Gnomish Lexicon, along with a set of related “strength” words (GL/60). But Gnomish also had a set of derivatives based on the elided primitive form ᴱ✶n’reu̯ such as G. †drio “hero” and driog “valiant” (GL/30). Derivatives with an initial n- continued to appear in Early Noldorin word lists from the 1920s, such as ᴱN. †nîr “hero, prince” and ᴱN. ne(i)rion “hero” (PE13/164).
In The Etymologies of the 1930s, the base root was ᴹ√DER “adult male, man (of any race)” with strengthened variant ᴹ√NDER “bridegroom”, but with the Quenya root becoming ᴹ√NĒR “man” under the influence of ᴹ√NĪ “woman” (Ety/DER, NDER, NĒR, NĪ); from this point forward Noldorin/Sindarin derivatives began with d-, such as S./N. dîr “man”. Likewise in Quendian & Common Eldarin Verbal Structure, also from the late 1930s, the root was given as ᴹ√(N)DER “man, male”, again as a strengthening of ᴹ√DER (EVS1: PE22/98). However, in the first version of Tengwesta Qenderinwa from the 1940s, the primitive root is given as ᴹ√NER “man” (TQ1: PE18/35) and likewise from the first version of Quenya Personal Pronouns from the late 1940s (QPP1: PE23/87).
Starting in the 1950s, Tolkien was more consistent in making the base root √NER with strengthened form √NDER. Tolkien gave √NDER/NER “male person” in Common Eldarin: Verb Structure (EVS2: PE22/133) and Common Eldarin: Noun Structure (PE21/70), both from the early 1950s. In the Quendi and Eldar essay from 1959-60 the base root was √NERE, though Tolkien clarified that the base root as referred more specifically to “physical strength and valour” (WJ/393). The root is given as √NER “man, male” in notes from the late 1960s (VT47/33).
This root for “(morally) good” and “holy” things dates back to Tolkien’s earliest versions of Elvish, probably due to its long-standing connection to the name Q. Manwë, one of the most stable names in Tolkien’s legendarium. The unglossed root ᴱ√MANA appeared in the Qenya Lexicon of the 1910s with derivatives like ᴱQ. mane “good (moral)” and ᴱQ. manimo “holy soul” (QL/58). Derivatives like G. mani “good (of men and character only), holy” and G. manos “spirit that has gone to the Valar” also appear in the contemporaneous Gnomish Lexicon (GL/56).
In The Etymologies of the 1930s ᴹ√MAN “holy spirit” appeared with derivatives like ᴹQ. manu/N. mân “departed spirit” (Ety/MAN). Earlier versions of the entry had the gloss “holy” (EtyAC/MAN), and an earlier version of the entry for ᴹ√MBAD has MAN- “blessed” (EtyAC/MBAD).
The senses “good, blessed, holy” were retained in Tolkien’s later writings, though sometimes the root was given in its augmented form √AMAN. In Quenya Notes (QN) from 1957, √MAN was contrasted with √ARA which also meant “good”, but with the nuance of one specimen that is “good of its kind” and hence “excels, without necessarily implying that others are bad or marred” (PE17/147). Elsewhere in QN Tolkien elaborated on the meaning of √MAN in more detail:
> √MAN “good”. This implies that a person/thing is (relatively or absolutely) “unmarred”: that is in Elvish thought unaffected by the disorders introduced into Arda by Morgoth: and therefore is true to its nature & function. If applied to mind/spirit it is more or less equivalent to morally good; but applied to bodies it naturally refers to health and to absence of distortions, damages, blemishes, &c (PE17/162).
In Definitive Linguistic Notes (DLN) from 1959, √AMAN “good (morally), holy, blessed, free from evil” was contrasted with √AYA(N) “treat with awe/reverence” and √MAGA “good (physically)” (PE17/149). In The Shibboleth of Fëanor from 1968, Tolkien said the root meant “blessed, holy” and was adapted from Valarin (PM/357 note #18), which is consistent with the fact that its derivatives were almost entirely limited to Quenya and not Sindarin; where derivatives do appear in Sindarin, such as S. Avon the equivalent of Q. Aman (PE17/162), they were probably loan words from Quenya.