weigh

Weigh is a verb with multiple related senses. In physics, weight is the gravitational force acting on a mass, expressed as W = m g. In everyday language, people frequently use weigh to mean mass, even though mass and weight are technically distinct quantities: mass is the amount of matter an object contains, while weight is the force gravity exerts on that mass.

Measuring weight involves scales and sensors. A balance scale uses known masses on one pan to balance an unknown mass on the other. A spring scale or electronic load cell measures force as gravity causes an extension or electrical response. Common units include newtons (N) for weight and kilograms (kg) or pounds (lb) for mass. On Earth, a 1 kilogram mass exerts a weight of about 9.81 newtons. Accuracy depends on proper calibration, zeroing (tare) of the scale, and controlling for container or background mass.

The word weigh also occurs in various idioms, such as weigh up (assess options), weigh in (contribute or declare an opinion), weigh the consequences (consider impact), and weigh anchor (prepare to depart). The term derives from Old English wegan, meaning to carry or bear weight. Historically essential to trade, agriculture, and science, weighing remains a fundamental method for quantifying mass, validating measurements, and informing decisions across many contexts.