Sentence:  He breathed now with his mouth open , showing a whitely curving section of lower <WSD>teeth</WSD> ; he kept his eyes , with their puffed blurred lids , always lowered , though not , apparently , focusing . 
Meaning of the word marked with <WSD> tags:  hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense