Definitions

flu

[floo] / flu /

NOUN

ailment

Synonyms

STRONGEST

ache condition disease disorder illness malady syndrome

STRONG

bug complaint dose indisposition infirmity

Antonyms

STRONGEST

health

NOUN

disease

Synonyms

STRONGEST

Cancer bug condition contamination defect disorder epidemic fever illness infection inflammation malady plague sickness stroke syndrome virus

STRONG

ache affection attack blight breakdown canker collapse complaint contagion convulsions debility decrepitude distemper endemic feebleness fit hemorrhage indisposition infirmity misery seizure spell temperature unhealthiness unsoundness upset visitation

WEAK

ill health pathosis sickliness

Antonyms

STRONGEST

advantage good health health

STRONG

ability blessing boon happiness soundness strength

NOUN

illness

Synonyms

STRONGEST

ailment breakdown collapse disability disorder disturbance ill health malady relapse seizure sickness syndrome virus

STRONG

affliction attack bug complaint confinement convalescence dose fit indisposition infirmity malaise prostration

WEAK

ailing diseasedness failing health poor health unhealth what's going around

Antonyms

STRONGEST

health order

STRONG

aid good health healthiness

WEAK

well-being wellness

NOUN

indigestion

Synonyms

STRONGEST

heartburn nausea

STRONG

acidosis dyspepsia flatulence gas pain

WEAK

acid indigestion digestive upset dyspepsy gaseous stomach

NOUN

infection

Synonyms

STRONGEST

bug disease epidemic pollution virus

STRONG

contagion corruption defilement germs impurity poison

WEAK

communicability contagiousness insanitation septicity what's going around

Antonyms

WEAK

sanitation sterility

NOUN

infirmity

Synonyms

STRONGEST

affliction ailment deficiency frailty ill health imperfection malady

STRONG

confinement debilitation debility decay decrepitude defect disease disorder failing fault feebleness indisposition malaise shortcoming unhealthiness unwellness vulnerability

WEAK

ailing diseasedness sickliness unhealth

Antonyms

STRONGEST

health perfection

STRONG

ability advantage improvement soundness strength strong point

WEAK

good health healthiness robustness

NOUN

insubstantiality

Synonyms

STRONG

affliction ailment confinement debilitation debility decay decrepitude defect deficiency delicacy disease disorder failing fault feebleness flimsiness fragility frailness frailty imperfection indisposition malady malaise puniness shortcoming unhealthiness unsoundness unwellness vulnerability weakness

WEAK

ailing delicateness diseasedness fragileness ill health sickliness unhealth unsubstantiality weakliness

Antonyms

STRONG

ability advantage health improvement perfection soundness strength strong point

NOUN

malady

Synonyms

STRONGEST

Cancer ache affliction ailment blight disability disorder epidemic fever illness infection infirmity inflammation sickness syndrome virus

STRONG

affection attack bug complaint condition contagion debility distemper plague

WEAK

ill health

Antonyms

STRONGEST

comfort good health health relief strength

NOUN

puniness

Synonyms

STRONG

affliction ailment confinement debilitation debility decay decrepitude defect deficiency delicacy disease disorder failing fault feebleness flimsiness fragility frailness frailty imperfection indisposition insubstantiality malady malaise shortcoming unhealthiness unsoundness unwellness vulnerability weakness

WEAK

ailing delicateness diseasedness fragileness ill health sickliness unhealth unsubstantiality weakliness

Antonyms

STRONG

ability advantage health improvement perfection soundness strength strong point

NOUN

unsoundness

Synonyms

STRONG

affliction ailment confinement debilitation debility decay decrepitude defect deficiency delicacy disease disorder failing fault feebleness flimsiness fragility frailness frailty imperfection indisposition insubstantiality malady malaise puniness shortcoming unhealthiness unwellness vulnerability weakness

WEAK

ailing delicateness diseasedness fragileness ill health sickliness unhealth unsubstantiality weakliness

Antonyms

STRONG

ability advantage health improvement perfection soundness strength strong point

NOUN

unsubstantiality

Synonyms

WEAK

affliction ailing ailment confinement debilitation debility decay decrepitude defect deficiency delicacy delicateness disease diseasedness disorder failing fault feebleness flimsiness fragileness fragility frailness frailty ill health imperfection indisposition insubstantiality malady malaise puniness shortcoming sickliness unhealth unhealthiness unsoundness unwellness vulnerability weakliness weakness

NOUN

weakliness

Synonyms

WEAK

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.

Many current vaccines, including seasonal flu shots and updated COVID-19 vaccines, are designed around virus strains already circulating in people.

From Science Daily • Jun. 5, 2026

The work is still in the early stages, but the team is already developing separate vaccines that could tackle flu and Ebola.

From BBC • Jun. 4, 2026

According to a press release from Sherrill's office, detainees have complained of undrinkable water, a lack of medical attention, and the spread of the flu and Covid-19 within the facility.

From Barron's • Jun. 2, 2026

On average, Ebola is about 50% fatal, which is far more deadly than flu or COVID-19.

From Salon • May 30, 2026

Victims of the flu often developed a secondary pneumonia caused by pneumococcus—an illness so rapid and fatal that doctors had termed it the “captain of the men of death.”

From "The Gene" by Siddhartha Mukherjee

flu

Example Sentences

Related Words