Istar noun "Wizard", used of Gandalf, Saruman, Radagast etc. Pl. Istari is attested. Gen. pl. in the phrase Heren Istarion "Order of Wizards" (UT:388). "The istari are translated wizards because of the connexion of wizard with wise and so with witting and knowing" (Letters:207); by this translation Tolkien tries to reproduce the relationship between Quenya istar and ista- #1, 2.
Quenya
istar
proper name. Wizard, (lit.) One Who Knows
Istar
wizard
ista
knowledge
ista (1) noun "knowledge" (IS). Also istya.
istarnië
feminine name. Istarnië
istare
noun. knowledge
istya
knowledge
istya noun "knowledge" (IS). Also ista (#1).
istari
Istari
The word comes from the verb ista- ("to know"), and possibly the agentive ending -ro.
-on
name
-on gen.pl. ending (3O), in aldaron, aranion, elenion, Eldaron, #esseron, Ingweron, Istarion, Númevalion, Quendion, Silmarillion, Sindaron, tasarion (see Nan-Tasarion), Valion, wenderon, yénion. Normally the ending -on is added to the nominative plural, whether it ends in -i or -r, but some nouns in -ë that would have nominative plurals in -i seem to prefer the ending -ron in the genitive (hence #esseron as the gen. pl. of essë "name", though the nominative pl. is attested as essi and we might have expected the gen. pl. *ession; similarly wenderon, Ingweron).
curuvar
wizard
curuvar _("k")_noun "wizard" (LT1:269 but Gandalf, Saruman etc. were istari)
Nolmë
knowledge, philosophy (including science)
Nolmë ("ñ")noun "knowledge, Philosophy (including Science)" (PM:360 cf. 344)
esse
noun. name
essë
name
essë (1) noun "name", also later name of Tengwa #31, originally (MET) called árë (ázë). (Appendix E). With a pronominal ending esselya "thy name" (VT43:14). Pl. #essi in PM:339 and MR:470, gen.pl. #esseron "of names" in the compound Nómesseron (q.v.); we would rather have expected *ession, given the nom.pl. essi; perhaps #esser is a valid alternative plural form. Essecarmë noun "name-making" (MR:214, 470), Eldarin ceremony where the father announces the name of his child. Essecenta *("k") noun "Name-essay" (see centa) (MR:415); Essecilmë noun "name-choosing", an Eldarin ceremony where a child named him- or herself according to personal lámatyávë (q.v.) (MR:214, 471). The meaning Tolkien originally assigned to the word essë** in the Etymologies was "place" rather than "name" (VT45:12).
essë
noun. name
esta-
verb. name
handë
knowledge, understanding, intelligence
handë noun "knowledge, understanding, intelligence" (KHAN). Note: *handë is (probably) also the past tense of the verb har- "sit".
issë
knowledge, lore
issë noun "knowledge, lore" (LT2:339; rather ista or istya in Tolkien's later Quenya)
sairon
wizard
sairon noun "wizard" (SAY); according to LT2:337 and GL:29, Sairon is also the Quenya (or Qenya) name of Dairon (Daeron).
sanda
name
[sanda, sandë] (þ) (2) noun "name" (VT46:16)
sanya
name
[sanya] (þ) (2) noun ?"name" (reading of gloss uncertain, VT46:16)
A name for the five Wizards who travelled from the West to aid the free peoples against Sauron (LotR/1084, UT/388). It usually appeared in its plural form Istari, which meant “those who know” (Let/202, PM/360). Tolkien generally translated the name as “Wizard”, because the Old English sense of word was similar to the true meaning of this Quenya word (Let/207). The name Istar was most likely a combination of the verb ista- “to know” and the old agental suffix -r(o).
The title Istar was not used for ordinary mortal “wizards” or “magicians” (UT/388). For this purpose, perhaps the word [ᴹQ.] sairon was used instead.