This root first appeared as ᴹ√RAS “stick up (intr.)” in The Etymologies of the 1930s with derivatives like ᴹQ. rasse and N. rhas or rhasg “horn (especially on living animal, but also applied to mountains)” (Ety/RAS; EtyAC/RAS). It reappeared as ᴹ√RASA “stick up” on an rejected page of roots in the Quenya Verbal System from the 1940s (PE22/127). Finally, √RAS “horn” appeared in Common Eldarin: Noun Structure of the early 1950s, but that was merely the last appearance of the root in Tolkien’s published writings. Q. rassë and S. rass “horn” continued to appear regularly as an element in mountain names in the 1950s and 60s.
Primitive elvish
oro
root. up(wards); rise (up), go high, mount
orǭmē
masculine name. Orome
orok
root. anything that caused fear or horror
dorno
noun. oak
rō/oro
root. up(wards); rise (up), go high, mount, up(wards); rise (up), go high, mount; [ᴹ√] high, [ᴱ√] steepness, rising
ornē
noun. (straight) tree
orta-
verb. to rise, ascend
ortā-
verb. to raise
orya-
verb. to rise
(s)rō Reconstructed
root. east
gō
preposition. from
keme
noun. earth
kemen
noun. earth
pū
noun. ‽
ras
root. horn, horn; [ᴹ√] stick up
skā
noun. ‽
skū
noun. ‽
ʒō
preposition. from
ambō
noun. hill
rass
noun. horn
ăwă
preposition. from
sisti
root. ‽
This invertible root had a long history in Tolkien’s writings. Its earliest iteration was in a pair of roots in the Qenya Lexicon of the 1910s: ᴱ√OŘO [OÐO] with derivatives having to do with the “dawn”, and ᴱ√ORO “steepness, rising” with which it was much confused (QL/70). The latter had derivatives like ᴱQ. orme “summit, crest, hilltop” and ᴱQ. orto- “raise” (QL/70), and Tolkien mentioned an inverted variant ᴱ√RŌ or ᴱ√ROHO with derivatives like ᴱQ. róna- “arise, rise, ascend” (QL/80). The contemporaneous Gnomish Lexicon also gave it as in an invertible root ᴱ√rō-, oro with derivatives like G. oros “rising” and G. ront “high, steep” (GL/63, 66).
The root reappeared in The Etymologies of the 1930s as ᴹ√ORO “up, rise, high” and ᴹ√RŌ “rise” (Ety/ORO, RŌ). The root was mentioned very frequently in his writings from the 1930s, 40s, 50s and 60s, generally glossed “rise” or “up(wards)”. Thus the root was very well established in Tolkien’s mind.