Definition: this is the ceasing of the existence of any particular species.

The definition given above is of the term "Extinction". 

In the biology, extinction refers to end of a living being or of a gathering of life forms , typically a species. The time of extinction or termination is for the most part thought to be the passing of the last individual of the species, in spite of the fact that the ability to breed and recoup may have been lost before this moment.