The Collaborative International Dictionary of English v.0.48:
Unalterable \Unalterable\ See alterable.WordNet (r) 3.0 (2006):
unalterable adj 1: not capable of being changed or altered; "unalterable resolve"; "an unalterable ground rule" [syn: unalterable, inalterable] [ant: alterable] 2: of a sentence; that cannot be changed; "an unalterable death sentence" 3: remaining the same for indefinitely long times [syn: changeless, unalterable]