Final answer:
Splenic ligament laxity or incompetence is the term used to describe the absence or weakness of one or more of the ligaments that hold the spleen in its normal position, allowing it to move or drift.
Step-by-step explanation:
An absence or weakness of one or more of the ligaments that hold the spleen in its normal position is called splenic ligament laxity or incompetence. This condition allows the spleen to drift or move out of its normal place. Splenic ligament laxity can result from various causes, such as trauma, underlying connective tissue disorders, or congenital abnormalities.