This Old English word means "to carry" or "to bear." While "weg" itself isn't commonly used today, it's the origin of many words related to weight, such as:
* Weigh: To determine the weight of something.
* Heavy: Having a great weight.
* Lightweight: Having a small weight.
So, "weight" ultimately comes from the idea of something being carried or borne, which makes sense considering its association with heaviness and the act of measuring how heavy something is.