lead line

noun Nautical.

1. a line by which a lead is lowered into the water to take soundings: in deep-sea practice, divided into levels one fathom apart, variously treated as marks and deeps.

noun

1. nautical a length of line for swinging a lead, marked at various points to indicate multiples of fathoms

n.

1. An irregular dark deposit in the gums occurring in lead poisoning.