pyrexia
noun
py·rex·ia pī-ˈrek-sē-ə 
: abnormal elevation of body temperature : fever
pyrexial
pī-ˈrek-sē-əl
adjective pyrexic
pī-ˈrek-sik
adjective 
Example Sentences
Recent Examples on the Web These included injection site reactions, headache, pyrexia (fever), fatigue, back pain, myalgia and rash. 
Ananya Bhattacharya, Quartz, 22 Dec. 2021 According to the US National Library of Medicine's MedlinePlus resource, a fever (aka, pyrexia) is technically a higher-than-normal body temperature. Leah Groth, Health.com, 2 Apr. 2020 For many of these reactions, the FDA database uses medical terminology, such as pyrexia and dyspnoea for fever and labored breathing, respectively. Ajc Homepage, ajc, 24 July 2017
Ananya Bhattacharya, Quartz, 22 Dec. 2021 According to the US National Library of Medicine's MedlinePlus resource, a fever (aka, pyrexia) is technically a higher-than-normal body temperature. Leah Groth, Health.com, 2 Apr. 2020 For many of these reactions, the FDA database uses medical terminology, such as pyrexia and dyspnoea for fever and labored breathing, respectively. Ajc Homepage, ajc, 24 July 2017 Word History
Etymology
New Latin, from Greek pyressein to be feverish, from pyretos
First Known Use
1777, in the meaning defined above
Medical Definition
pyrexia
noun
py·rex·ia pī-ˈrek-sē-ə
: abnormal elevation of body temperature : fever