futtock shroud: shroud that is part of a ship's rigging
sheet: (nautical) a line (rope or chain) that regulates the angle at which a sail is set in relation to the wind
absolute zero: (cryogenics) the lowest temperature theoretically attainable (at which the kinetic energy of atoms and molecules is minimal); 0 Kelvin or -273.15 centigrade or -459.67 Fahrenheit