die off
phr. v..phr. v.. to die one by one until there are none left.
phr. v.. to undergo a gradual process of extinction or mass expiration within a group or population until few or none remain.
The flowers are dying off because of the frost.
Many local businesses died off during the economic crisis as people stopped spending money on luxury items.
Biologists are concerned that the native bee population is dying off due to the widespread use of industrial pesticides.
usually refers to a group, species, or collection of things rather than a single individual.
contrast with 'die out' (used for entire species or traditions becoming extinct) and 'die down' (used for sounds or intensity decreasing).
The last dinosaur died off in the forest.The last dinosaur died in the forest.'die off' implies a group process over time; use 'die' for a single individual's death.