Derf (adj.) - brave, powerful, difficult, hard.
Miles 2: So late lede hym belyve and lenge her no lenger,
To ser Pilate oure prince oure pride will we prayse.Miles 3: Yoa, he may synge or he slepe of sorowe and angir,
For many derfe dedes he has done in his dayes.Miles 4: Now wightly late wende on oure wayes,
Late vs trusse vs, no tyme is to tarie.- Anonymous: The York plays (1440)
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
http://www.pbm.com/~lindahl/concise/concise.html
The example text was found at the Middle English Collection of the University of Virginia Library.
http://etext.virginia.edu/collections/languages/english/mideng.browse.html