The word sheep is used for all creatures of a certain species; it is the superordinate term of ewe, lamb, ram, etc.[1]
We can also say that two or more words that share the same superordinate term are co-hyponyms. So, dog and horse are co-hyponyms and the superordinate term is animal.[2]
The only possible superordinate term for the hyponyms – cow and bull is cow, which is identical with one of the hyponyms; the term cattle is a collective term, while bovine is only technical.[3]
In this tradition, the term hypernym is used to designate a superordinate term, hyponym to designate a subordinate term, and co-hyponym to designate a coordinate term.[4]