[Gil-Galad]

The Hidden City, The Hidden Rock, Ondolindë, The Rock of the Music of Water

are four that i can remember right now...theres also Gondolin so thats five...now 2 more


Edit: 2 other names that could mean Gondolin, Tumladen, which is the valley and the encircleing mountains


Edit#2: The round valley of Tumladen, within the Encircling Mountains, had originally been a lake, and in its centre stood a hill that had once been an island: Amon Gwareth. It was here that Turgon decided to found his Hidden City, as a memorial to ancient Tirion that lay beyond the Great Sea

if you include City with Seven names its seven names!!!