The actual Tolkienian text [well, a later-ish one] is
The Tale of Years [First Age], an added entry [528>]
"532: Elros and Elrond twin sons of Earendil born." JRRT, The War of The Jewels
Also,
The Tolkien Gateway article quoted above contains a possible conflation in my opinion [not that quoting it means you agree with everything in it, Evil Shieldmaiden, this just gives me a chance to blather on again about names]. The impression in the entry refers to a scenario Tolkien described in a letter written in 1958, that
Elros and
Elrond got their names from being found in a cave with a waterfall over the entrance, Elrond in the cave, Elros dabbling in the water. Here
Elrond means
"Elf-cave [as in a cavern]", and
Elros means
"Elf-spray, [of fall or fountain; ros could also mean dew]"But years later [possibly more than a decade later] Tolkien imagines a different scenario: in texts dated 1968 [or later] it's Elwing who names Elros
"Star-foam" and Elrond
"Star-dome", their names being formed to recall her name, the word
ros meaning
"foam, the white crest of waves, or spindrift as of water blown by the wind or falling steeply over rocks" [note
Cair Andros "Ship of Long Foam" in The Lord of the Rings,] and
Elrond contains a word for
the starry firmament, the starry dome, given in memory of the Menelrond in Menegroth.Quote:
Etymology from Tolkien Gateway: Elros is a Sindarin name meaning "Elf of the spray", based on a tale from his early childhood when the Sons of Fëanor abducted the twins until Maedhros found them playing in a forest waterfall. Alternatively, his name could mean "star-foam".
Alternatively? Yes
as "Star-foam" is the later idea.
I get that both these ideas existed in a "1950s context or later" [and granting a notion of confusion between "star and elf words" too], but that doesn't necessarily mean that Tolkien meant for both these meanings to be internal... just sayin'...
... anyway... I likes names