Final answer:
Sir Gawain is special for 3 hours a day (9 AM - noon) because he becomes invisible. This is seen in the quote provided: "A bow-shot from her bower-eaves, He rode between the barley-sheaves, The sun came dazzling through the leaves And flamed upon the brazen greaves Of bold Sir Lancelot." During these hours, Sir Gawain is able to move undetected and unseen by others.
Step-by-step explanation:
The question is referencing a characteristic of Sir Gawain from Arthurian legends. Specifically, it's asking about an ability he posesses during a particular period of the day (from 9 AM to noon). The legend of Sir Gawain, much like those of other Arthurian knights, often includes magical or supernatural elements.
According to Arthurian legend, one of Sir Gawain's special attributes was that he gained great strength as the sun rose to its peak, becoming strongest at noon but then gradually losing strength as the sun set. Therefore, the answer to what is special about Sir Gawain for 3 hours a day is that he gains great strength.