plumb line
Noun: A plumb line is a simple tool consisting of a cord with a heavy, pointed weight (called a plumb bob) attached to one end. When suspended, the weight points directly toward the earth's center of gravity, providing a precise reference line that is perfectly vertical or "plumb."
The plumb line is used primarily in construction, carpentry, and surveying to establish or check true vertical alignment. * The carpenter used a plumb line to ensure the wall was perfectly straight. * Before hanging the door, check its alignment with a plumb line.
- "To drop a plumb line": This phrase describes the action of using the tool.
- The surveyor dropped a plumb line from the bridge to measure the exact height above the water.
- Figurative Use: It can be used metaphorically to mean a standard for testing truth, uprightness, or accuracy.
- His moral integrity served as a plumb line for the entire community.
- Plumb (verb): To test or measure depth or alignment with a plumb line; to examine closely.
- He plumbed the depth of the well.
- The book plumbs the complexities of human nature.
- Plumb bob (noun): The pointed metal weight at the end of a plumb line.
- Plumb rule (noun): A narrow board with a plumb line attached, used by masons and carpenters.
- Perpendicular: A line at a right angle to a given line or plane. (While related, this is a geometric term, not a tool.)
- Vertical reference: A general term for anything used to establish a vertical line.
- Out of plumb: Not vertically straight.
- That old tower is several inches out of plumb.
- Plumb in the middle: Exactly in the center. (This idiom derives from the tool's association with precision.)
- He hit the target plumb in the middle.
The plumb line is one of the oldest and most reliable tools for determining a true vertical. Its principle is based solely on gravity, making it accurate regardless of location or technological availability.
- a cord from which a metal weight is suspended pointing directly to the earth's center of gravity; used to determine the vertical from a given point