febrile
adjective
fe·brile ˈfe-ˌbrī(-ə)l 
also
ˈfē- : marked or caused by fever : feverish
a febrile reaction caused by an allergy
Did you know?
Not too surprisingly, febrile originated in the field of medicine. We note its first use in the work of the 17th-century medical reformer Noah Biggs. Biggs used it in admonishing physicians to care for their "febrile patients" properly. Both feverish and febrile are from the Latin word for "fever," which is febris. Nowadays, febrile is used in medicine in a variety of ways, including references to such things as "the febrile phase" of an illness. And, like feverish, it also has an extended sense, as in "a febrile emotional state."
Example Sentences
Recent Examples on the Web Scholars have universally dismissed Geoffrey’s text as a pseudo-history, woven from ancient Welsh folk tales and his febrile imagination. 
Joshua Hammer, Smithsonian Magazine, 24 Aug. 2022 In Brazil, like the United States, the idea that the voting system is routinely manipulated by corrupt officials and unscrupulous partisans has become a delusion of the febrile right-wing hive mind. Andre Pagliarini, The New Republic, 27 July 2022 The febrile 48 hours from April 18-20 last year was also during the annual meeting of UEFA’s 55 member federations, held in Montreux, Switzerland. Graham Dunbar, ajc, 10 July 2022 The course of the COVID-19 pandemic, however, has proven an especially febrile period for Johnson. Liam Hess, Vogue, 7 July 2022 French authorities approved the drug for sale in September of 1988, amid an already febrile atmosphere. Lauren Collins, The New Yorker, 5 July 2022 As Sam starts digging, we are transported back to 1964, where febrile schoolboy crushes abound and students are enraptured by one particularly charismatic teacher. The New Yorker, 20 June 2022 Singing lines and lush harmonies briefly give way to short, fitful solos by violin and viola, played with febrile intensity by concertmaster Robert Chen and guest principal violist Ben Ullery. Hannah Edgar, Chicago Tribune, 6 May 2022 Then there are the internal debriefings that make up Frances’ narration, which capture the febrile workings of the young-woman brain in all their relentless, vulnerable glory. San Diego Union-Tribune, 13 May 2022 See More
Joshua Hammer, Smithsonian Magazine, 24 Aug. 2022 In Brazil, like the United States, the idea that the voting system is routinely manipulated by corrupt officials and unscrupulous partisans has become a delusion of the febrile right-wing hive mind. Andre Pagliarini, The New Republic, 27 July 2022 The febrile 48 hours from April 18-20 last year was also during the annual meeting of UEFA’s 55 member federations, held in Montreux, Switzerland. Graham Dunbar, ajc, 10 July 2022 The course of the COVID-19 pandemic, however, has proven an especially febrile period for Johnson. Liam Hess, Vogue, 7 July 2022 French authorities approved the drug for sale in September of 1988, amid an already febrile atmosphere. Lauren Collins, The New Yorker, 5 July 2022 As Sam starts digging, we are transported back to 1964, where febrile schoolboy crushes abound and students are enraptured by one particularly charismatic teacher. The New Yorker, 20 June 2022 Singing lines and lush harmonies briefly give way to short, fitful solos by violin and viola, played with febrile intensity by concertmaster Robert Chen and guest principal violist Ben Ullery. Hannah Edgar, Chicago Tribune, 6 May 2022 Then there are the internal debriefings that make up Frances’ narration, which capture the febrile workings of the young-woman brain in all their relentless, vulnerable glory. San Diego Union-Tribune, 13 May 2022 See More Word History
Etymology
Medieval Latin febrilis, from Latin febris fever
First Known Use
1651, in the meaning defined above
Medical Definition
febrile
adjective
fe·brile
ˈfeb-ˌrīl also ˈfēb-
: marked or caused by fever : feverish