In agriculture, a Bumper Crop is a crop that has yielded an unusually productive harvest. In agriculture, a Bumper Crop is a crop that has yielded an unusually productive harvest. A Bumper Crop can also be a source of problems, such as when there is insufficient storage space (barns, grain bins, etc.) for an overlarge crop. The word 'Bumper' has a second definition meaning 'something unusually large', which is where this term comes from. The term 'bumper crop' has also been used to refer to a similar large result in other activities, or as a pun such as with a group of automobiles (for their front/rear bumpers).