IPA: //ʌnˈsɪŋkəbl//
KK: /ʌnˈsɪŋkəbl/
Describing a ship or object that cannot be sunk, often because it is designed with special features to prevent sinking.
The Titanic was once thought to be unsinkable, but it tragically sank on its maiden voyage.
Unsinkable → It is formed from "un-" (meaning not) and "sink" (from Old English "sincan", meaning to go down or descend) and "-able" (meaning capable of). The word "unsinkable" means not capable of sinking or going down.
Think of something that is 'not' ('un-') able to 'go down' ('sincan') — that's why unsinkable means it cannot sink.