- unbreakable - impossible to break especially under ordinary usage; "unbreakable plastic dinnerwear"
Antonyms: breakable, brittle, brickle, brickly, crumbly, delicate, fragile, frail, frangible, splintery, friable
- unbreakable - impossible to not honor; "an unbreakable promise"
Antonym: violable (indirect, via inviolable)