topon. Tindrock, (lit.) Isle of the Great Steeples
An island in S. Nen Hithoel translated “Tindrock” (LotR/373), but more literally meaning “Isle of the Great Steeples” (PE17/22, PE17/61). The first element of this name is tol “island”, but the origin of the second element is unclear. In one place, Tolkien indicated it was an elaboration of brand² “steeple” (PE17/22, PE17/61), in another that it was a corruption of baradnir “tower-steep” (RC/333).
Conceptual Development: In Lord of the Rings drafts from the 1940s, Tolkien considered many different names for this island: first N. Toll-ondren “Carrock” with many minor variations (TI/268, 285) and then N. Tolharn or Tollernen “Stoneait” (TI/324), revised to N. Eregon “Stone Pinnacle” (TI/345), briefly N. Emris before reverting back to Eregon (TI/367) and then finally N. Tol Brandor >> Tol Brandir (TI/359, 367).