aggregate fruit

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A fruit, such as the raspberry, consisting of many individual small fruits derived from separate ovaries within a single flower, borne together on a common receptacle.

Wiktionary

1. n. botany A fruit that develops from the fusion of more than one carpel within a single flower, as for instance, a raspberry.

WordNet 3.0

1. n. fruit consisting of many individual small fruits or drupes derived from separate ovaries within a common receptacle: e.g. blackberry; raspberry; pineapple.