plumb bob

noun

1. plummet ( def 1 ).

plumb bob

noun

1. the weight, usually of lead, at the end of a plumb line; plummet

Word History and Origins

Origin of plumb bob¹

First recorded in 1825–35

Example Sentences

Now, you can use a plumb bob or level to project down to the ground exactly where your support posts will be.

From Seattle Times

But the installation titled “Diver” features a stainless-steel plumb bob swinging elliptically over the level surface of a container of water that sits on the Guggenheim’s sloping ramp.

From Washington Post

As it swings, the shiny plumb bob reflects onto the water the orange and yellow sunset in a nearby photograph, which is pegged to an armature connected to a rotating fan.

From Washington Post

Don’t stare and plumb bob forever, but don’t hurry, either; wait that extra half-second until that projected putt becomes, somehow, real in the mind.

From Golf Digest

Something else conjectured by Newton in the Principia was that a plumb bob hung near a mountain would incline very slightly toward the mountain, affected by the mountain’s gravitational mass as well as by the Earth’s.

From Literature