Partial shipment is a term that can be applied in 2 types of delivery scenarios.
First, we have shipments that are intended to be shipped in parts. In this scenario, a shipper and a buyer agree that goods will be transported not in a single batch but separately.
The other scenario is one where an order was supposed to be delivered in full. Just like in the case above, there are individual items in the order - but the customer never agreed to receive them in part.