What term describes a deep, steep-walled, V-shaped valley cut by a river?

The term that describes a deep, steep-walled, V-shaped valley cut by a river is canyon. Canyons typically form through the erosion of rock by flowing water over long periods. The process of erosion carves out the steep sides, resulting in the distinctive V-shape that characterizes many canyons. They can also be quite expansive, showcasing impressive geological features and formations.

While "gorge" is similar in meaning and can also refer to a narrow valley with steep, rocky sides, the term "canyon" is more widely used to describe broader areas with more significant depth and width, often associated with river systems. The term "valley" is more general and can apply to many types of landforms, not specifically the steep-walled formations characterized by the V-shape mentioned in the question. Lastly, "creek" refers to smaller bodies of flowing water, not the landform itself. Thus, canyon is the specific and suitable term for this type of geographical feature.