Sentence:  This combination shirt, of which the seat was made of <WSD>wash-leather</WSD>, protected the whole body down to the knees... 
Meaning of the word marked with <WSD> tags:  Leather that has been treated so as to be very absorbent. Usually made of sheepskin treated with oil, and used for dusting or as an absorbent lining in pockets, gloves, etc.