flu(redirected from 'flu)
Also found in: Dictionary, Thesaurus, Medical.
acute, highly contagious disease caused by a RNA virus (family Orthomyxoviridae); formerly known as the grippe. There are three types of the virus, designated A, B, and C, but only types A and B cause more serious contagious infections.
..... Click the link for more information. .
1. short for influenza
2. any of various viral infections, esp a respiratory or intestinal infection