Translation (to represent the language of Rohan) of the Elvish name Angrenost. 361, 373-7
NÃºmenÃ³rean stronghold in the valley called, after its occupation by the wizard CurunÃr (Saruman), Nan CurunÃr, at the southern end of the Misty Mountains; translation (to represent the language of Rohan) of the Sindarin Angrenost. See also Circle of Isengard.
The fortress of Saruman.
A Gondorian fortification at the southern end of the Misty Mountains, at the source of the River Isen. It was granted to the Wizard Saruman by Steward Beren of Gondor, and destroyed by the Ents during the War of the Ring, though its central tower of Orthanc remained standing.
The name means 'iron enclosure'. Isengard wasn't literally made of iron, of course - the word isen, 'iron', refers to the exceedingly hard rock from which it was actually made.