Enzymes that cleave monomers (sometimes also di- or oligomers) from one end of a polymer chain. Exonucleases are able to cleave
nucleotides, one by one, from either the 5- or the 3- (or both) ends of
nucleic acids.
Source:
PAC, 1992, 64, 143
(Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992))
on page 153