Final answer:
A delta is the geological feature that forms where a river meets a larger body of water, created by the deposition of sediments from the river.
Step-by-step explanation:
The feature that may form where a stream enters a lake or ocean is called a delta. A delta is an often triangular-shaped section of land formed when the flowing waters of a river slow down as they enter a larger body of water, such as a lake or ocean. The river splits into many smaller channels called distributaries, depositing the sand, silt, and sediments it has carried downriver. These deposits build up over time to create the delta formation, which can be influenced by waves, tides, or the river's current. Large rivers like the Nile, Amazon, and Mississippi are known for their significant deltas.