Noun

1. A heat stroke or fever, often suffered in the tropics.
   • 1719: Daniel Defoe, Robinson Crusoe

     Yet even in this voyage I had my misfortunes too; particularly that I was continually sick, being thrown into a violent calenture by the excessive heat of the climate.

2. A delirium occurring from such symptoms, in which a striken sailor pictures the sea as grassy greens and wishes to dive overboard into them.