any of a class of enzymes that catalyse the formation of covalent bonds and are important in the synthesis and repair of biological molecules, such as DNA
ligase in American English
(ˈlaɪˌgeɪs; ˈlaɪˌgeɪz)
noun
any of a class of enzymes that act as catalysts in chemical reactions in which molecules are linked together, as in the synthesis and repair of DNA or in the formation of recombinantDNA