From Longman Dictionary of Contemporary Englishfluflu /fluː/ ●●● S2 noun [uncountable] MIa common illness that makes you feel very tired and weak, gives you a sore throat, and makes you cough and have to clear your nose a lot SYN influenza Steven’s still in bed with flu. She’s got the flu. I couldn’t go because I had flu.a flu virus/bug the spread of the flu virus Doctors now fear a flu epidemic.
Examples from the Corpus
flu• Flu shots are recommended for people 55 and older.• It is unknown how m any of those pneumonia cases were preceded by flu.• Campbell, however, was suffering from flu yesterday and a decision on his fitness will not be made until today.• Only replacement back Kenny Logan was an absentee, confined to bed suffering from the 24-hour flu bug.• Pace of flu attack hits 14-year high.• The guard said he has played a little sluggish because of the flu and an ankle sprain he suffered two weeks ago.• The economy had not just a passing cold but a bad case of the flu.• When Cottingham was 16, she got what she thought was the flu.flu epidemic• Fortunately, full-blown flu epidemics are relatively rare.• Ah, that was the time we had a spring flu epidemic.• Jane died in the flu epidemic in 1916.Origin flu (1800-1900) influenza 