Pose (n.) - a cold in the head, a cough.
For, were it wyn, or oold or moysty ale,
That he hath dronke, he speketh in his nose,
And fneseth faste, and eek he hath the pose.
He hath also to do moore than ynough
To kepen hym and his capul out of the slough;
- Chaucer, Geoffrey: The Canterbury tales (1387-1394)
The Middle-English Word of the Day is selected from Mayhew and Skeat's
"Concise Dictionary of Middle English."
As found on Greg Lindahl's website
The example text was found at the Middle English Collection of the University of Virginia Library.