infective

adjective

in·​fec·​tive in-ˈfek-tiv 

: infectious:

a

: producing or capable of producing or transmitting infection

… infective oocysts are ingested with contaminated feed or water.

—Douglas N. Stern

Affected cats not yet showing signs of illness may shed the virus and be infective to other cats …

—Cat Fancy

b

: caused by or resulting from an infection with one or more pathogenic agents

infective bacterial endocarditis

c

: affecting others : spreading easily to others

Different teachers will demonstrate different skills and strengths. Some will have … an infective enthusiasm for their own subject.

—Jonathan Glazzard et al.

Examples of infective in a Sentence

Recent Examples on the Web

The parasite becomes infective one to five days after it is passed in the feces of the cat. — Joe Mutascio, The Indianapolis Star, 21 Aug. 2023

His provisional cause of death was given as multi-organ failure due to infective endocarditis, a rare infection of the inner lining or valves of the heart. — Daniel Taylor, The Athletic, 26 Feb. 2025

People typically get malaria by being bitten by an infective female Anopheles mosquito. — Sara Moniuszko, CBS News, 5 Oct. 2023

Symptoms usually appear seven to 30 days after an infective bite and include high fever, chills, body aches, diarrhea and vomiting, Maryland health department officials said. — Minnah Arshad, USA TODAY, 19 Aug. 2023

Word History

Etymology

Middle English infectif "causing disease, infectious," borrowed from Medieval Latin infectīvus "infectious, poisonous" (Latin, "used for dyeing"), from Latin infectus, past participle of inficere "to dye, discolor, taint, contaminate with disease" + -īvus -ive — more at infect

First Known Use

14th century, in the meaning defined above

Phrases Containing infective

• anti-infective

Rhymes for infective

• advective
• affective
• collective
• connective
• convective
• corrective
• defective
• detective
• directive
• effective
• elective
• injective

Kids Definition

infective

adjective

in·​fec·​tive in-ˈfek-tiv 

: producing or able to produce infection

infectivity

(ˌ)in-ˌfek-ˈtiv-ət-ē 

noun

Medical Definition

infective

adjective

in·​fec·​tive in-ˈfek-tiv 

: infectious:

a

: producing or capable of producing or transmitting infection

… infective oocysts are ingested with contaminated feed or water.

—Douglas N. Stern

… a strain of bacteria which forms spores that can remain infective for as long as fifty years.

—Sue Hubbell

Affected cats not yet showing signs of illness may shed the virus and be infective to other cats …

—Cat Fancy

b

: caused by or resulting from an infection with one or more pathogenic agents

infective bacterial endocarditis