So, on what finger do you wear a promise ring? In the USA and the UK, the ring finger (fourth finger) of the left hand holds the greatest significance; engagement rings and wedding rings are worn on this finger almost without exception.
In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively.
Learner's definition of EXTINCTION. : the state or situation that results when something (such as a plant or animal species) has died out completely. [noncount]. the extinction of all life in the region. Several bird species are threatened with extinction. = Several bird species are on the brink of extinction.