noun.
Any of various very small New World monkeys of the genera Callithrix and Cebuella, having a long tail and long incisors that they use to penetrate bark to extract gum and sap.
The Century Dictionary and Cyclopedia
noun.
A little ape or monkey.
noun.
Now, specifically, a small squirrel-like South American monkey of the family Hapalidæ, or Mididæ (which see for technical characters).
noun.
An ugly little fellow; a conceited “puppy.”
the GNU version of the Collaborative International Dictionary of English
noun.
Any one of numerous species of small South American monkeys of the genera Hapale and Midas, family Hapalidæ. They have long soft fur, and a hairy, nonprehensile tail. They are often kept as pets. Called also squirrel monkey.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
small soft-furred South American and Central American monkey with claws instead of nails
Word Usage
"Each individual marmoset is an amalgam of cells from two different marmosets."