Start to dredge North Yorkshire river - you may have to work at it (4)
I believe the answer is:
desk
But I can't explain it at all! Could you help me understand?
(Other definitions for desk that I've seen before include "Place for writing or serving the public" , "Secretaire" , "Flat surface for doing paper work" , "Escritoire - service counter" , "Table for writing, reading etc" .)