1. The dimensions, extent, amount, or degree of something, in terms of how large or small it is: William and Ann picked a table which they thought was the right size for their dining room.
2. Something that is large, often very large, in dimensions or degree: Did you see the size of the neighbor's dog?
3. A set of measurements used when making, or classifying, articles; such as, clothing or shoes that are produced and sold according to various sizes.
4. Etymology: from Old French sise, a shortened form of Old French assise, past participle of asseoir, "to settle"; from Latin assidere, "to sit beside", from Latin sedere, "to sit".

To cut, shape, or manufacture goods so that they have the necessary or chosen measurements desired: Hank had his suit sized specifically to fit his body.