relapsing fever


Definition of relapsing fever

: a variable acute epidemic disease that is marked by recurring high fever usually lasting three to seven days and is caused by a spirochete (genus Borrelia) transmitted by the bites of lice and ticks

First Known Use of relapsing fever

1828, in the meaning defined above

Buying Guide

Our team at The Usage has selected the best thermometers.

Learn More About relapsing fever

Time Traveler for relapsing fever

Time Traveler

The first known use of relapsing fever was in 1828

See more words from the same year

Dictionary Entries Near relapsing fever


relapsing fever


See More Nearby Entries 

Statistics for relapsing fever

Cite this Entry

“Relapsing fever.” Dictionary, Merriam-Webster, Accessed 24 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for relapsing fever

relapsing fever


Medical Definition of relapsing fever

: a variable acute infectious disease that is marked by sudden recurring episodes of high fever which usually last from three to seven days, are typically accompanied by myalgia, arthralgia, headache, nausea, and chills, and often end in a crisis stage marked by a spike in fever followed by an afebrile period and that is caused by a spirochete of the genus Borrelia (as B. hermsii, B. parkerii, or B. recurrentis) that circulates in the blood and is transmitted by the bite of a body louse (Pediculus humanus humanus) or a tick of the genus Ornithodoros — see mianeh fever

More from Merriam-Webster on relapsing fever Encyclopedia article about relapsing fever


Test Your Vocabulary

Name that Thing: Flower Edition

True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!