PITCH n.
adapted for working with a sprocket wheel. -- Pitch line, or Pitch circle (Gearing), an ideal line, in a toothed gear or rack, bearing such a relation to a corresponding line in another gear, with which the former works, that the two lines will have a common velocity as in rolling contact; it usually cuts the teeth a…
PLANE n.
An ideal surface, conceived as coinciding with, or containing, some designated astronomical line, circle, or other curve; as, the plane of an orbit; the plane of the ecliptic, or of the equator.
THYROID a.
Of or pertaining to the thyroid body, thyroid cartilage, or thyroid artery; thyroideal. Thyroid cartilage. See under Larynx. -- Thyroid body, or Thyroid gland (Anat.), a glandlike but ductless body, or pair of bodies, of unknown function, in the floor of the mouth or the region of the larynx. In man and most mammals i…