an organism living in or on another organism and drawing its nourishment directly from it, often harming it in the process
a person who depends on somebody else for existence or support without making a useful or adequate return
parasitic /-ʹsitik/ adj
parasitical /-ʹsitikl/ adj
parasitically /-ʹsitikli/ adv
[early French parasite via Latin from Greek parasitos, from para-1 + sitos grain, food]