\Ful"crum\, n.; pl. L. {Fulcra}, E. {Fulcrums}. [L.,
bedpost, fr. fulcire to prop.]
1. A prop or support.

2. (Mech.) That by which a lever is sustained, or about which
   it turns in lifting or moving a body.

3. (Bot.) An accessory organ such as a tendril, stipule,
   spine, and the like. [R.] --Gray.

4. (Zo["o]l.)
   (a) The horny inferior surface of the lingua of certain
       insects.
   (b) One of the small, spiniform scales found on the front
       edge of the dorsal and caudal fins of many ganoid
       fishes.

5. (Anat.) The connective tissue supporting the framework of
   the retina of the eye.