dingy: [18] Nobody is quite sure where dingy comes from, but the very occasional occurrence of ding or dinge as Middle English forms of dung suggests that it may originally have signified ‘dung-coloured’ (although if it came from such a source it might have been expected to rhyme with springy rather than stingy). Dung [OE] itself appears to go back ultimately to an Indo-European base *dhengh- denoting ‘covering’ (relatives include the Lithuanian verb dengti ‘cover’), so its etymological significance is ‘material spread over the earth (for fertilization)’ rather than ‘excrement’. => dung
