PRESSOR a.
Causing, or giving rise to, pressure or to an increase of pressure; as, pressor nerve fibers, stimulation of which excites the vasomotor center, thus causing a stronger contraction of the arteries and consequently an increase of the arterial blood pressure; -- opposed to depressor. Landois & Stirling.…
PRISM n.
ally flint glass and crown glass, the difference of dispersive power being compensated by giving them different refracting angles, so that, when placed together so as to have opposite relative positions, a ray of light passed through them is refracted or bent into a new position, but is free from color. -- Nicol's pri…
PROBABLE a.
Rendering probable; supporting, or giving ground for, belief, but not demonstrating; as, probable evidence; probable presumption. Blackstone. Probable cause (Law), a reasonable ground of presumption that a charge is, or my be, well founded. -- Probable error (of an observation, or of the mean of a number), that within…
PROMISE v.
To engage to do, give, make, or to refrain from doing, giving, or making, or the like; to covenant; to engage; as, to promise a visit; to promise a cessation of hostilities; to promise the payment of money. "To promise aid." Shak.
PUMICE n.
volcanic scoria, usually of a gray color, the pores of which are capillary and parallel, giving it a fibrous structure. It is supposed to be produced by the disengagement of watery vapor without liquid or plastic lava. It is much used, esp. in the form of powder, for smoothing and polishing. Called also pumice stone.…