Recalcitrant means stubbornly refusing to obey rules, follow directions, or cooperate, even when it would be wise or reasonable to do so. A recalcitrant student might repeatedly ignore their teacher's instructions, not because they don't understand them, but because they've decided they simply won't comply. A recalcitrant mule famously refuses to move, no matter how much you coax or pull.

The word carries a sense of deliberate, persistent resistance. It's stronger than simply being reluctant or hesitant. Someone who's recalcitrant has dug in their heels and won't budge, often making things harder for themselves and everyone around them. A recalcitrant computer program might refuse to install updates, or a recalcitrant engine might refuse to start despite your efforts to fix it.

While standing up for what's right sometimes requires refusing to go along with the crowd, recalcitrant usually describes resistance that's unreasonable or counterproductive. The emphasis is on being difficult and uncooperative when cooperation would actually help. After all, there's a difference between having the courage of your convictions and simply being stubborn for its own sake.