rope used to secure the weight of a limb in rigging; load line.
drop line (Wikipedia)
A dropline is a commercial fishing device, consisting of a long fishing line set vertically down into the water, with a series of fishing hooks attached to snoods.
Droplines may be set either down underwater cliffs or just in the water column. They have a weight at the bottom of the line and a float at the top. They are not usually as long as longlines and have fewer hooks.
Droplines can be contrasted with trotlines. Whereas a dropline has a series of hooks suspended vertically in the water, a trotline has a series of hooks suspended horizontally in the water.