Definition of "flu-like"

However, caffeine withdrawal can bring on symptoms like headache, fatigue or drowsiness, difficulty concentrating, depressed mood or irritability, and even flu-like symptoms such as nausea or muscle pain!

2014, Kristen Mancinelli, The Ketogenic Diet, page 121

He had presented in the Cromwell Hospital, London with flu-like symptoms and initially received treatment for related renal bleeding.

2015, Justin D. Edwards, Technologies of the Gothic in Literature and Culture, page 113

The most common adverse effects include injection-site redness and swelling, menstrual irregularities, flu-like symptoms (eg, fever, chills, and myalgias), and rarely injection-site necrosis.

2017, Joseph T. DiPiro, Robert L. Talbert, Gary C. Yee, Pharmacotherapy