noun Nautical. a block used in raising or lowering a topgallant yard.
jack block 🔊 Listen to this noun Nautical. a block used in raising or lowering a topgallant yard. Jack Block, 85, Psychologist Who Studied Children Into Adulthood Jack Block Jr. Announces Campaign To Return To Council | The B-Town 3608M – Trailer Jack Block Jack Block Stock Photos & Jack Block Stock Images – Alamy 3608M – Trailer Jack Block Share Facebook Twitter Google +