leadline

Etymology 1

lead + line (verb "to lead")

noun

1. A leash or strap for leading an animal.

Etymology 2

lead + line (after the metal); the attached plummet is usually made from lead.

noun

1. A sounding line; an instrument used in navigation to measure water depth.
   Approximately 60% of inshore hydrography was acquired by leadline (pre-1940) sounding technology. 2004, 2004 Atlantic Boating Almanac: Gulf of Mexico
2. (fishing) A weighted line for holding down the lower edge of a gillnet.
   To attach the bridles, start measuring from the point on the gavel 16 metres from the floatline wheree you have seized the end of the leadline. 1987, M. Ben-Yami, Purse-seining with Small Boats, page 46
   The hold was empty, without a net, corkline, leadline or buoy to be found. 1993, Dana Stabenow, A Fatal Thaw, page 103
   Generally, there will be equal selvedges to the floatline and leadline. 1987, Ludvik Karlsen, Bjorn A. Bjarnason, Small-scale Fishing with Driftnets, page 33