The verb nam- “judge” appeared in 1968 notes associated with the The Shibboleth of Fëanor, attested in the phrase namin alasaila “I judge [it] unwise” (VT41/13). This version of the verb is consistent with the name Námo, given in The Silmarillion as the true name of Mandos (S/28).

In a marginal note within Late Notes on Verb Structure (LVS) from 1969 Tolkien revised the root to √NDAB “to judge” with a new form Návo to replace Námo (PE22/154 note #53). These notes initially had nem- for “judge”, revised to ham- and finally to nav- (PE22/154 note #53, 55, 56); it was after all these revisions that he coined the new root √NDAB.

The verb nav- “judge” appeared in several phrases:

• la năvin karitalya(s) mára “I do not advise you to do so, (lit.) I don't judge your doing (it) good”
• lá karitas, navin, alasaila ná “not doing this would be (I think) unwise”
• alasaila ná lá kare tai mo nave mára “it is unwise not to do what one judges good”

Based on the above phrases, it seems the basic sense of the verb is “judge” or “think = *have as an opinion”.

Conceptual Development: Tolkien introduced the name Námo in the 1950s, which is probably where this concept originated. It seems to have remained √NAM up through 1968, and then nam- >> nem- >> ham- >> nav- in 1969.

Neo-Quenya: For purposes of Neo-Quenya, I prefer to use the form nam- “judge, *think [have as an opinion]” for consistency with the name Námo in The Silmarillion as published.