Definition from Wiktionary, the free dictionary
- (uncountable) The condition of being a twin
- (countable, nautical) Either of a pair of ships of exactly the same design
- 1858 Charles Arad Joy et. al. - Addresses of the Newly-appointed Professors of Columbia College
- In this twinship of right and duty lies the embryonic genesis of liberty . . .
- 1837 Edward Pelham Brenton - The Naval History of Great Britain
- The Royal George, a twinship, was nearly as much approved of; and these two ships, by their fast sailing, were the principal, causes of the defeat of the enemy's fleets . . .