Wordnet 3.0
NOUN (1)
1.
a tiny granule in the cytoplasm that is where protein synthesis takes place under the direction of mRNA;
The Collaborative International Dictionary of English v.0.48:
microsome \microsome\ n. (Cell biology)
a tiny granule in the cytoplasm of a cell; it consists of
ribosomes bound to fragments of the endoplasmic reticulum and
mitochondria.
[WordNet 1.5 +PJC]
WordNet (r) 3.0 (2006):
microsome
n 1: a tiny granule in the cytoplasm that is where protein
synthesis takes place under the direction of mRNA