Sentence:  Again, Beside these parts destin'd to divers offices, there is a peculiar provision for the wind-pipe, that is, a cartilagineous <WSD>flap</WSD> upon the opening of the Larynx or Throttle, which hath an open cavity for the admiffion of the air 
Meaning of the word marked with <WSD> tags:  Anything broad and flexible that hangs loose, or that is attached by one side or end and is easily moved.