1865, from bump + -y (2). Fasten your seatbelts. It will likely be a bumpy evening. [Bette Davis ("Margo Channing"), "About Eve," 1950] Relevant: Bumpiness.
covered with or packed with lumps
- causing or described as jolts and unusual movements
The intruder rode slowly on the bumpy forest trail but as soon as he reached a paved roadway, Howie lost him.