Sentence:  Now that she had rested and had fed from the luncheon tray Mrs. Broome had just removed, she had reverted to her normal gaiety.  She looked cool in a grey tailored cotton dress with a terracotta scarf and shoes and her hair a black silk <WSD>helmet</WSD>. 
Meaning of the word marked with <WSD> tags:  A protective head covering, usually part of armour.