opportunistic
Americanadjective
-
adhering to a policy of opportunism; practicing opportunism.
-
Pathology.
-
(of a microorganism) causing disease only under certain conditions, as when a person's immune system is impaired.
-
(of a disease or infection) caused by such an organism.
Pneumocystis pneumonia is an opportunistic disease that often strikes victims of AIDS.
-
adjective
-
of or characterized by opportunism
-
med (of an infection) caused by any microorganism that is harmless to a healthy person but debilitates a person whose immune system has been weakened by disease or drug treatment
Other Word Forms
Etymology
Origin of opportunistic
First recorded in 1890–95; opportunist + -ic
Explanation
To be opportunistic is to quickly take advantage of a situation, usually in a way that's just plain wrong. You know how an opportunity is a chance to do something? When you're opportunistic, you take advantage of that chance, usually immediately. Most of the time, this word is not neutral: people described as opportunistic are also considered unethical, like a business taking advantage of employees or customers in an opportunistic way. If someone dropped their wallet and someone else found it and kept it, that would be opportunistic. Being opportunistic is shady and self-serving.
Vocabulary lists containing opportunistic
This Week In Culture: March 29–April 4, 2020
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
“Mandatory Vaccination is Not the Answer to Measles” by Bob Sears
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
This Week In Culture: October 19–25, 2019
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The chance of opportunistic aggression isn’t zero, but the record suggests it’s unlikely.
From The Wall Street Journal • May 21, 2026
Analysts at 22V Research see the Aragchi visit as an opportunistic move by Beijing to signal it could nudge each side to a compromise,
From Barron's • May 6, 2026
Investors active during the financial crisis will remember a flurry of opportunistic deals with Goldman Sachs, Bank of America, Dow Chemical and GE, and also Berkshire’s acquisition of railway BNSF.
From The Wall Street Journal • May 1, 2026
However, like the modern octopus, they would have been opportunistic and voracious predators, and wouldn't have passed up other prey if they had the chance.
From BBC • Apr. 23, 2026
Gravity is opportunistic, amplifying even small condensations of matter.
From "Cosmos" by Carl Sagan
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
