plumb

Everyday

1. (verb) To fit water pipes in a building: «plumb in a washing machine». tree →
2. (noun) A weight on a string (a plumb line or plumb bob) used to check that something is exactly vertical or to measure depth. tree →
3. (adjective) Exactly vertical, perfectly upright. tree →
4. (verb) To measure the depth of water; «plumb the depths» means reach the deepest or worst point. tree →
5. (informal, adverb, mainly US) Completely or exactly: «plumb crazy», «plumb in the middle». tree →

In the lessons

In science and DT lessons, a plumb line shows the true vertical because gravity pulls the weight straight down. Builders use it for walls. Sailors once used a weighted line to plumb the depth. Plumbers fit pipes. In everyday talk: «plumb the depths of despair».

Examples

• The builder used a plumb line to check the wall. tree →
• The wall is not plumb; it leans. tree →
• Dad plumbed in the new dishwasher. tree →
• Sailors plumbed the depth of the river. tree →
• Gravity pulls the plumb bob straight down. tree →
• «You're plumb crazy!» said the cowboy. tree →
• The ball landed plumb in the middle of the target. tree →

Note

The «b» is silent: say PLUM. Homophone trap: «plum» (the fruit). Plumber, plumbing come from Latin «plumbum», lead, because old pipes were made of lead (chemical symbol Pb).