Most shipping jargon is not decoration: each term names a rule that decides what a label costs or when a parcel arrives. Dimensional weight, cubic pricing, residential surcharges and postage-due adjustments all change the number on the invoice. These 32 definitions say what the term means and when it applies to you.
Each definition is deliberately short and links out to the page that answers the money question, because the rate table, not the definition, is where the decision gets made.