Where does febrile come from?

The first records of febrile come from the mid-1600s. It comes from the Latin febrīlis, from the Latin febris, “fever.” This root serves as the basis of many related words, including fever itself, febricity (“the state of being feverish”), febriferous (“producing fever”), febrifacient (“something that produces fever”), febricula (“a slight and short fever”), febrific (“marked by fever”), and febrifuge (“a medicine to reduce fever”).

Febrile is most often seen in medical situations involving fevers and their effects. Febrile illnesses are those that are usually accompanied by a fever. It is also used in the names of specific conditions like febrile convulsion (an effect of high fever in young children that involves involuntary shaking).

People sometimes use febrile to describe a situation or atmosphere with a lot of uncertainty, instability, or anxious excitement, as in the febrile period before the election. Similar things are implied by the term feverish and the phrase fever pitch (meaning “a high degree of excitement”). All of these terms reference the kind of delirious state that can accompany a high fever.