Definition of ram-line in English:

ram-line

noun

Shipbuilding
historical
  • A thin line or cord used to mark a straight middle-line on a spar or mast, or (stretched between the bow and stern) to form the sheer of a ship.

Origin

Mid 17th century. Apparently from ram + line. Compare later ram.

Pronunciation

ram-line

/ˈramlʌɪn/