Yardang
Rock that has developed a streamline form because of wind erosion. The long axis of these features is aligned with the dominant wind direction.
Y-axis
Vertical axis on a graph.
Yearling
An animal that is in its second year of life. A spike bull elk, for example, is a yearling that is 1 1/2 years old in the fall of its second year.
Yellow Snow
Snow that is given golden, or yellow appearance by the presence of pine or cypress pollen in it.