A piece of lead attached to a line, used in sounding the depth of water, a plumb bob or a plumb line
Hence, any weight
A piece of lead formerly used by school children to rule paper for writing (that is, to mark with rules, with lines)
A plummet line, a line with a plummet; a sounding line
Violent or dramatic fall
A decline; a fall; a drop
To drop swiftly, in a direct manner; to fall quickly.