Aranwë is a Noldorin Elf of Gondolin, most notable as the father of Voronwë (who plays a significant role in the story of Tuor's coming to Gondolin in the First Age). The references in the texts to Aranwë are limited to less than half-dozen or so. One is grasping at straws to draw any hard conclusions for additional information drawn from those few mentions of his name. When Voronwë arrives at the gates of Gondolin bringing Tuor with him, he introduces himself as the son of Aranwë.
Then he spoke proudly, saying: ‘Know you not whom you see? I am Voronwë son of Aranwë of the House of Fingolfin. Or am I forgotten in my own land after a few years? Far beyond the thought of Middle-earth I have wandered, yet I remember your voice, Elemmakil.’
Readers have speculated that when he says, "of the House of Fingolfin," he does not necessarily mean that he is a close kinsman of Fingolfin. Instead, they suggest that this nomenclature means, more likely than not, that he was one of those who followed Fingolfin's host out of Aman and into Middle-earth, as opposed to those counted themselves among the faction of the Noldor loyal to Fëanor.
Aranwë is mentioned only twice in The Silmarillion. The first is in a passage within the story of Tuor's quest for Gondolin:
But in the morning when the storm was passed, Tuor came upon an Elf standing beside the walls of Vinyamar; and he was Voronwë, son of Aranwë, of Gondolin, who sailed in the last ship that Turgon sent into the West.
The other time his name comes up is in the "Index of Names."
Aranwë Elf of Gondolin, father of Voronwë.
Aranwë is not even mentioned in earliest version of The Fall of Gondolin published in The Book of Lost Tales Part Two, wherein his son Voronwë is sometimes called Bronweg. The wife of Aranwë, mother of Voronwë, is mentioned in the Unfinished Tales version and said to be a kinswoman of Círdan. Voronwë tells Tuor a little of history own history in the Unfinished Tales' version of Tuor's story, saying,
I was born here in Middle-earth in the land of Nevrast. My mother was of the Grey-elves of the Falas, and akin to Círdan himself – there was much mingling of the peoples in Nevrast in the first days of Turgon’s kingship – and I have the sea-heart of my mother’s people.
For one who is not a language expert, references to the construction of Aranwë’s name in the texts are indirect and/or difficult to ferret out; in other sources, they are at times direct but largely not footnoted. Most sources indicate that it is possibly a combination of the Sindarin or, more likely than not, Quenya noun aran (meaning king or noble) added to the not uncommon ending of -wë, which is used for both male and female names (for example, Finwë or Elenwë, among others). Another possible root is ara, meaning noble.
The name construction would not necessarily seem to be of great importance on the surface. However, a number of readers use it as the linchpin of an argument that Aranwë might not have been simply a noble from among the followers of Fingolfin who ended up finally in Gondolin, but could possibly have been an actual member of Fingolfin's immediate family. The aran component of his name has been used as the basis of an argument that Aranwë is somehow of a line of kings. This suggestion has surfaced again and again over the years. In the discussion thread of an article posted on Tumblr written by Erunyauve called "Elven Royal Roots," Curufinwefeanaro states it simply: "There’s been an interesting suggestion of Aranwë being son of Lalwen and thus Voronwë being Ñolofinwë’s grand-nephew." Lalwen, of course, is Fingolfin's sister [see SWG bio Írimë (Lalwen)]. As a nephew of Lalwen, Aranwë could be considered of royal blood but not in the direct line of succession, since Fingolfin had surviving sons.
This suggestion is not new. Michael Martinez touched upon it in his well-known article, "It’s All in the Family: The Finwëans," originally published in 2001.
As provided in the Shibboleth, Irien (originally called Irime, the third daughter) was born between Fingolfin and Finarfin. She was also called Lalwende, and it was this name which was Sindarinized into Lalwen. She and Fingolfin were very close and she accompanied him into exile. We hear nothing more of her, but some people have wondered if Aranwe, the father of Voronwe, might not be Lalwen’s husband or son.
Clearly the Lalwen speculation is interesting, proven by the fact that it has captured the imagination of more than one generation of Tolkien readers, but there is no direct canonical basis for it.
All that we actually know from the texts is that Aranwë is Noldorin, almost certainly of noble or lordly status, that he lived in the city of Gondolin, that he fathered a son named Voronwë, and that his unnamed wife was related to Círdan.