er·gas·tic \|ər|gastik\adjective Etymology: Greek ergastikos able to work, industrious, from (assumed) ergastos (verbal of ergazesthai to work) + -ikos -ic : constituting the nonliving by-products of protoplasmic activity < ergastic materials > — used chiefly of intracellular deposits (as of starch or fat) or of extracellular secretions; compare metaplasm