'Mudder' definitions:

Definition of 'mudder'

(from WordNet)
noun
A racehorse that runs well on a muddy racetrack

Definition of 'Mudder'

From: GCIDE
  • Mudder \Mud"der\, n.
  • 1. a racehorse that exhibits a better than usual performance when the racetrack is wet or muddy. [PJC]
  • 2. An athlete who performs better than his/her average under muddy conditions. [PJC]