INVINCIBLE
invincible, unbeatable, unvanquishable
(adjective) incapable of being overcome or subdued; “an invincible army”; “her invincible spirit”
Source: WordNet® 3.1
Etymology
Adjective
invincible (not comparable)
Impossible to defeat, destroy or kill; too powerful to be defeated or overcome.
Synonyms: unconquerable, undefeatable
Antonyms: conquerable, defeatable, vincible, weak
Noun
invincible (plural invincibles)
Someone or something that cannot be defeated, destroyed or killed.
Antonym: vincible
Source: Wiktionary
In*vin"ci*ble, a. Etym: [L. invincibilis: cf. F. invincible. See In-
not, and Vincible.]
Definition: Incapable of being conquered, overcome, or subdued;
unconquerable; insuperable; as, an invincible army, or obstacle.
Lead forth to battle these my sons Invincible. Milton.
– In*vin"ci*ble*ness, n.
– In*vin"ci*bly, adv.
Source: Webster’s Unabridged Dictionary 1913 Edition