ruddlePronunciation: /ˈrʌd(ə)l/Definition of ruddle noun [mass noun] another term for reddle. a small block of reddle or a similar substance that is attached to the chest of a ram to mark the ewe that it tups. Origin: late Middle English: related to obsolete rud 'red colour' and red; compare with raddleruddle in other Oxford dictionaries Definition of ruddle in the US English dictionary