Definition
A device used for weighing, consisting of two pans suspended from a horizontal bar that is supported in the middle. An object of known weight is placed in one pan, and the object to be weighed is placed in the other to determine its mass.
The pharmacist used a pair of scales to precisely measure the weight of the medicine.
In the old market, merchants still use a pair of scales to measure goods.
To ensure a fair trade, they used a pair of scales to weigh the gold.