Of a ship that cannot be sunk mainly due to fortified walls and clever engineering.(adjective)
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Use "unsinkable" in a sentence
"The Titanic was not called "unsinkable" - without qualificatio - until AFTER she sank, when the VP stated "I thought her unsinkable...""
"Today, the old Harland and Wolff shipyard in Belfast, in which the Titanic was built, is home to a new project commemorating the so-called unsinkable ship."
"The Titanic, which was dubbed unsinkable before it hit an iceberg and foundered in the north Atlantic in April 1912, is at the centre of plans to rejuvenate a large part of the city's docklands."