opportunistic

adjective

op·​por·​tu·​nis·​tic ˌä-pər-tü-ˈni-stik 

-tyü-

: taking advantage of opportunities as they arise: such as

a

: exploiting opportunities with little regard to principle (see principle sense 1) or consequences

a politician considered opportunistic

an opportunistic investment

b

: feeding on whatever food is available

opportunistic feeders

opportunistic bears

c

: being or caused by a usually harmless microorganism that can become pathogenic when the host's resistance is impaired

opportunistic infections

opportunistic diseases

opportunistically

ˌä-pər-tü-ˈni-sti-k(ə-)lē 

-tyü-

adverb

Examples of opportunistic in a Sentence

Recent Examples on the Web

Where compliance assumes rational actors, red teams will simulate malicious insiders, confused contractors or opportunistic intruders. —Jochen Schwenk, Forbes.com, 4 June 2025

This is now the second opportunistic urban skill that's been observed in the large-bodied cockatoo (Cacatua galerita), a very social species found along the southern, eastern and northern coastline of Australia, as well as Indonesia and Papua New Guinea. —New Atlas, 4 June 2025

Evan weakened and soon died of an opportunistic infection. —Nicholas Kristof, Mercury News, 3 June 2025

Loss of community trust Trans and nonbinary people have often been studied under opportunistic and demeaning circumstances. —Paz Galupo, The Conversation, 2 June 2025

Word History

Etymology

opportunist + -ic entry 1

First Known Use

1892, in the meaning defined above

Rhymes for opportunistic

• anachronistic
• animalistic
• antagonistic
• antiphlogistic
• behavioristic
• cannibalistic
• capitalistic
• characteristic
• collectivistic
• deterministic
• ethnolinguistic
• expressionistic

Kids Definition

opportunistic

noun

op·​por·​tu·​nis·​tic -t(y)ü-ˈnis-tik 

: taking advantage of opportunities as they arise: as

a

: exploiting opportunities with little regard to principle or consequences

an opportunistic cheater

b

: feeding on whatever food is available

opportunistic feeders

Medical Definition

opportunistic

adjective

op·​por·​tu·​nist·​ic -t(y)ü-ˈnis-tik 

1

: of, relating to, or being a microorganism that is usually harmless but can become pathogenic when the host's resistance to disease is impaired

2

: of, relating to, or being an infection or disease caused by an opportunistic organism

Pneumocystis carinii pneumonia and other opportunistic infections that kill AIDS patients

—New York Times