Sentence:  A crib-biting horse repeatedly seizes fixed objects with its incisor teeth and pulls back while making a characteristic grunting noise that signifies the passage of air into the esophagus. A <WSD>wind-sucker</WSD> achieves the same characteristic neck posture and grunt without holding onto any fixed object. It is believed that crib-biters may become wind-suckers ... 
Meaning of the word marked with <WSD> tags:  A horse with the habit of windsucking.