Also found in: Dictionary.
(as) dry as dust
1. Very dry. I followed the recipe exactly, and yet my cake is as dry as dust. I need to take out my contact lenses now because my eyes are just dry as dust.
2. Lacking any interesting or engaging elements; very boring. That lecture on polynomials almost put me to sleep—it was just dry as dust.
mod. dull; lifeless. I can’t take another one of his dry-as-dust lectures.