The most important and complex symbol in Sir Gawain is the girdle Lady Bertilak offers to Gawain, which he accepts. Lady Bertilak presents the girdle to Gawain as a token to remember her by, but its true significance lies in its ability to protect the wearer from injury. Because Gawain has promised to allow the Green Knight to strike him with his ax, the girdle gives Gawain a chance to survive the blow.

Gawain takes the girdle with its potential usefulness in mind, but he does not present it to Lord Bertilak that evening in accordance with their agreement; in this way, the girdle comes to symbolize Gawain’s cowardice in the face of possible death, as well as his disloyalty and deceit. After the Green Knight reveals his true identity, Gawain therefore adopts the girdle as a sign of his weakness and as a way of doing penance for his misdeeds.

Gawain’s return to court adds another layer of meaning to the girdle. After Gawain recounts his story and explains his reasons for wearing the girdle, everyone at court reacts with laughter before then deciding to also wear a similar green sash. In light of their initial derision of Gawain’s story, the court’s decision is unexpected; one reading of the court’s decision to stand by Gawain involves the possibility that the court eventually recognizes the sincerity of Gawain’s remorse and wishes to honor it as itself a marker of good character.