nonsinkable

/ˌnɑnˈsɪŋkəbəl/
adjective
  1. Not able to sink; designed to stay afloat in water.
    • Engineers tested the nonsinkable hull in rough seas.
    • They claimed the new raft was completely nonsinkable.
    • The lifeboat was made of nonsinkable materials.
  2. Figuratively, unable to fail or be defeated; very resilient.
    • He had a nonsinkable belief that everything would work out.
    • Her nonsinkable optimism kept the team going through hard times.
    • The company's nonsinkable reputation survived the scandal.
Antonyms
What does "nonsinkable" mean? | whatsthatwordmean | whatsthatwordmean