Which term describes an animal that is one year old or in its second year?

The term that describes an animal that is one year old or in its second year is "yearling." This term specifically refers to animals, often livestock, that are at the age range of one to two years. For example, in the context of cattle, a yearling is typically a young animal that has surpassed the calf stage but has not yet reached full maturity.

In contrast, "lamb" refers specifically to a young sheep that is less than one year old. "Cubil" is not a widely recognized term in the context of animal age or classification, and it may not refer to any specific animal category. "Calf," on the other hand, denotes a young cattle that is still in its first year of life. Therefore, "yearling" is the correct term that encapsulates the age of an animal that is either one year old or in its second year.