The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: An enzyme of macromolecular size due to unusual biopolymerization or immune complexing, such as when a normal enzyme is protein-bound, typically by immunoglobulins (antibodies); macroenzymes by themselves are not always pathophysiologic or pathogenic, but their occurrence is increased in certain diseases (their formation is encouraged by some pathogenetic processes). Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.