noun.
An individual carpel of a schizocarp, having a single seed
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a carpel with one seed; one of a pair split apart at maturity
Word Usage
"Each half fruit (mericarp) is tipped by a persistent style, and marked by vertical ribs, between or under which lie, in many genera, the oil tubes or vittæ."