mulishness n the trait of being difficult to handle or overcome Usage(s) Anyone who saw her I Shot Andy Warhol, with Lili Taylor as would-be assassin Valerie Solanas, could spot the Canadian-born Oxford graduate's mulishness and taste for beguiling . What the mules lacked in speed they made up "for in mulishness. The President was showing his mulishness. Synonym(s) stubbornness obstinacy obstinance