Sentence:  His hand went to her shoulder and pushed aside the knotted scarf that surmounted the striped poplin <WSD>gown</WSD> ; then , to better purpose , he took hold of the knot and with dextrous fingers , untied it . 
Meaning of the word marked with <WSD> tags:  a woman's dress, usually with a close-fitting bodice and a long flared skirt, often worn on formal occasions