exonuclease
noun
exo·nu·cle·ase ˌek-sō-ˈnü-klē-ˌās 
-ˈnyü-,
-ˌāz
: an enzyme that breaks down a nucleic acid by removing nucleotides one by one from the end of a chain compare endonuclease
Example Sentences
Recent Examples on the Web One of these advantageous proteins is an enzyme called exonuclease (ExoN), which helps the virus proofread and correct copies as they are made. 
Mark Fischetti, Scientific American, 23 June 2020 Double stranded DNA fragments with overlapping sequence stretches are inserted into a reaction, and exonuclease enzymes chew back one end of each piece, exposing complementary sequences that link up, joining the two fragments together. Jeffrey Marlow, WIRED, 31 Mar. 2015
Mark Fischetti, Scientific American, 23 June 2020 Double stranded DNA fragments with overlapping sequence stretches are inserted into a reaction, and exonuclease enzymes chew back one end of each piece, exposing complementary sequences that link up, joining the two fragments together. Jeffrey Marlow, WIRED, 31 Mar. 2015 Word History
First Known Use
1963, in the meaning defined above
Medical Definition
exonuclease
noun
exo·nu·cle·ase ˌek-sō-ˈn(y)ü-klē-ˌās, -ˌāz
: an enzyme that breaks down a nucleic acid by removing nucleotides one by one from the end of a chain compare endonuclease