Silmarien (sometimes "-riën") fem. name, apparently incorporates sil(i)ma (Appendix A) and the feminine ending -ien, or -rien as a variant of -riel (garlanded maiden) as in Altariel (Galadriel).
Quenya
silmarien
feminine name. Silmarien
Silmarien
-riën
Eldest child of Tar-Elendil and ancestor of Valandil of Andúnië (LotR/1035, S/268). Her name seems to be a compound of [ᴹQ.] silma “silver, shining white” and the feminine suffix -ien.