(botany) An aggregate fruit comprised of achenes, drupelets, follicles, or berries.
Sometimes the achenia are aggregated upon a common receptacle, forming what is called an etaerio, as in the ranunculus, in which they are placed upon a dry receptacle, or in the strawberry, in which the receptacle is fleshy.
1953, John Melvin Lowson, Textbook of Botany, University Tutorial Press, page 318,
Clematis: actinomorphic; 4 petaloid sepals; petals 0; fruit an etaerio of achenes with persistent hairy styles.