Sentence:  The original "<WSD>slops</WSD>" were voluminous breeches of about knee length, reminiscent of 17th century "petticoat breeches", worn with stockings; these continue to be depicted as late as 1790s, but trousers, first introduced as slop-clothing in 1720s, were more functional and more popular. 
Meaning of the word marked with <WSD> tags:  Sailors' breeches ending just below the knees or above the ankles, worn mainly in XVIII century.