The phrase "nasty flu" refers to a very bad or severe case of influenza, a contagious illness that affects the respiratory system and makes people feel very sick.
Sentences with «nasty flu»
Executives at several seniors housing REITs say the burdens of more supply coming on - line this year are being complicated by a particularly nasty flu season. (nreionline.com)
Wish I could spend more time outside but I'm stuck inside because of a very nasty flu. (dcinstyle.com)