parasitic

American  

[par-uh-sit-ik] / ˌpær əˈsɪt ɪk /

Sometimes parasitical

adjective

1. of, relating to, or characteristic of parasites.

2. (of diseases) due to parasites.

3. Phonetics. excrescent.

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Other Word Forms

• antiparasitic noun
• antiparasitical adjective
• antiparasitically adverb
• nonparasitic adjective
• nonparasitical adjective
• nonparasitically adverb
• parasitically adverb
• parasiticalness noun
• pseudoparasitic adjective
• unparasitic adjective
• unparasitical adjective
• unparasitically adverb

Etymology

Origin of parasitic

1620–30; < Latin parasīticus < Greek parasītikós. See parasite, -ic

Explanation

The adjective parasitic is mainly a scientific term for talking about an organism that lives on a host, taking what it needs to stay alive while often injuring the host. By their nature, ticks, leeches, and lice are all parasitic; they live off their hosts. You can also use the word parasitic more metaphorically, to describe a person who takes without giving anything in return. A thirty year-old man who lives with his mother, eating her food and not paying rent, could be described as parasitic, since he survives by sponging off another person. Parasitic comes from the Greek word parasitos, "eating at another's table."

Example Sentences

Irwin Mitchell solicitors said its clients had reported contracting gastric illnesses such as E coli, salmonella and shigella, and parasitic infections such as cryptosporidium.

From BBC • Apr. 7, 2026

The spread of New World screwworm in Mexico, a parasitic fly that can infect livestock, adds another layer of uncertainty.

From Barron's • Mar. 5, 2026

The common and highly contagious parasitic infection can cause diarrhea in animals as well as people.

From Los Angeles Times • Feb. 13, 2026

"With more than 3,000 species of spiders alone, Brazil has immense potential for discovering new parasitic mites," says Bassini-Silva.

From Science Daily • Jan. 28, 2026

Dr. Pickett himself was a pioneer in the field of working out sane methods of insect control that take full advantage of the predatory and parasitic species.

From "Silent Spring" by Rachel Carson