Feverish means hot with fever, or restlessly excited. Feel feverish, feverish activity, a feverish night.
The medical sense is literal and the other is a metaphor of the same heat: feverish activity is fast, unfocused and slightly desperate. Feverish speculation is what markets do before something breaks, and the word chooses itself in that phrase.
1adjectivefeverishHot with fever, or restlessly excited.
“The child was feverish all night, so we called the doctor in the morning.”
feverish is a state.
Proto-Indo-European
*dʰegʷʰ- — to burn
Latin
febris — a fever
Old French
fievre — fever
Old English
fefer
Middle English
fever
English
fever
English, today
feverish
Built from
From fever + -ish. fever comes from Middle English fever, fevere, from Old English fefer, fefor (“fever”) and Old French fievre (“fever”), from Latin febris (“a fever”), from Proto-Indo-European dʰegʷʰ- (“to burn”). Displaced native Old English hriþ (“fever”). Compare also stq Fiewer, German Fieber, Danish feber, Swedish feber.
Etymology from Wiktionary, CC BY-SA