sír noun "river", shorter form of sirë (PE17:65, VT49:17)
Quenya
sírë
river
sír
river
sír(ë)
noun. river, river, [ᴱQ.] stream
The most common Quenya word for “river”, derived from the root √SIR “flow”.
Conceptual Development: This word first appeared as ᴱQ. sīre “stream” as a derivative of ᴱ√SIŘI [SIÐI] (QL/84), and this form and gloss also appeared in the contemporaneous Poetic and Mythological Words of Eldarissa (PME/84). The form ᴹQ. siri- “river” appeared in the Declension of Nouns (DN) from the early 1930s, along with uninflected sire with short i and various inflected forms with siry- (PE21/10). The form sīre “river” with long ī appeared in The Etymologies of the 1930s as a derivative of ᴹ√SIR “flow” (Ety/SIR; EtyAC/SIR). In several notes from the mid-1960s, it appeared in monosyllabic form sír (PE17/65) or sīr (VT49/17), but it had dual form siryat from the late 1960s implying a stem form of sirĭ- and a development similar to that of DN from the early 1930s (VT47/11).
Neo-Eldarin: Its form síre is probably better known and more commonly used in Neo-Quenya. For example this is the typical form in Helge Fauskanger’s NQNT (NQNT).
celusindi
river
celusindi _("k")_noun "river" (LT1:257; hardly a valid word in Tolkien's later Quenya, where the terms sírë and sirya appear instead)
nen
river
nen noun "river" (LT1:248), "river, water" (LT1:262) (In Tolkien's later Quenya, nén with a long vowel means "water", but hardly "river" - that is sírë.)
sindi
river
sindi noun "river" (LT1:265; rather sírë in LotR-style Quenya)
sirya
river
#sirya noun "river", attested in the dual form siryat (VT47:11). Compare sírë.
celu
stream
celu _("k")_noun "stream" (LT1:257; rather celumë in LotR-style Quenya)
celumë
stream, flow
celumë ("k")noun "stream, flow" (KEL, LT1:257); locative pl. celumessen ("k") in Markirya (ëar-celumessen is translated "in the flowing sea", lit. *"in sea-streams").
hlóna
river, especially given to those at all seasons full of water from mountains
[hlóna (2) noun "a river, especially given to those at all seasons full of water from mountains" (VT48:27; the word is marked with a query and the note containing it rejected; it was apparently replaced by lón, q.v.)]
nuinë
suffix. river
sirya-
verb. to flow, to flow [smoothly]
This verb first appeared in the Quenya Verbal System (QVS) from 1948 as an example of ya-formative half-strong verb ᴹQ. siry(a)- “flow” (PE22/114), though its primitive form ᴹ✶siryă “flow smoothly” appeared a bit earlier in Quendian & Common Eldarin Verbal Structure (EVS1) from the late 1940s (PE22/98). This verb may have replaced the basic verb ᴹQ. sir- “flow” from The Etymologies of the 1930s (Ety/SIR), but see Conceptual Development below.
The verb sirya- continued to appear [albiet without translation] as an example of half-strong verb conjugation in Tolkien’s writings in the 1960s with a past form sirinye (PE17/77; PE22/164). In one place he conjugated it as a weak verb from primitive ✱siryā with weak past siryane (PE22/156), but this may have been a transient or experimental idea.
Conceptual Development: QVS from 1948 has a present-tense form síra as part of the sentence númen Endorello isse sí Vaia síra “westward of Middle-earth where now Ocean flows” (PE22/126). It is not entirely clear which verb it is the present tense for. It looks like the present tense of the basic verb ᴹQ. sir- “flow” from the 1930s, but could have been intended to be the present of the sirya- “flow” instead, since that is the verb for “flow” everywhere else in QVS.
Based on the discussion of half-strong verbs QVS, I would expected the present tense of sirya- to be the long imperfect ✱siryalya; compare the present imperfect taltalya “am slipping down” for half-strong talta- (PE22/115). Such long imperfects were used for the present tense of verbs with otherwise defective presents, the main example being a-verbs such as fara- “hunt” whose present was faralya “is hunting” (PE22/116). But Tolkien also said “some verbs make a strong present, so ōla-, is growing [from ola-]”. Thus síra might be an example of such a strong present for half-strong sirya.
Neo-Quenya: For purpose of Neo-Quenya, I would assume sirya- was the most common Quenya verb for “to flow”, conjugated as a ya-formative half-strong verb. I would further assume that, like in EVS1, sirya- has the implied meaning of “flow [smoothly]”. However, I would assume ᴹQ. sir- is a less commonly used verb for “flow”, especially applicable when flows are turbulent or not continuous, as in the “the Ocean is flowing [síra]” in the sentence given above. For example, Helge Fauskanger used sir- “flow” in his NQNT (NQNT).
sírë noun "river" (SIR, VT46:13), "stream" (LT1:265). Also short form sír, q.v.Compare #sirya.