Sentence:  The milk-mirror, or <WSD>escutcheon</WSD>, is formed by the hair above the udder, extending upwards between the thighs, ... 
Meaning of the word marked with <WSD> tags:  A marking upon the back of a cow's udder and the space above it (the perineum), formed by the hair growing upward or outward instead of downward. It was once taken as an index of milking qualities.