> Nobody would have snickered if the Titanic were described as unsinkable by people who had been trying to sink it for 10 years.

Pedantic: I'm sure somebody would have snickered about "unsinkable" if the Titanic sank after 10 years. Pragmatic: if the "unsinkable" Titanic lasted 10 years (or at least to profitability) before being sunk by people intending to sink it, that might certainly count as being "unsinkable" for the time it hadn't sunk.

Hubris: Titanic was claimed to be unsinkable before it was launched.