measure (the depth of a body of water)

I plumbed the depth and found the bottom of the shelf to be seven metres down

test (an upright surface) to determine the vertical

they are valuable aids in plumbing the frames and keeping the side of the ship fair

a ball of lead or other heavy object attached to the end of a line for finding the depth of water or determining the vertical on an upright surface

exactly

trading opportunities plumb in the centre of central Europe

vertically

drapery fell from their human forms plumb down

vertical

ensure that the skirting is straight and plumb

install an appliance such as a bath, toilet, or washing machine and connect to water and drainage pipes

he had plumbed in a second-hand washing machine