1. Ability, regarded as put forth or exerted; strength, force, or energy in action; as, the power of steam in moving an engine; the power of truth, or of argument, in producing conviction; the power of enthusiasm. The agent exercising an ability to act; an individual invested with authority; an institution, or government, which exercises control; as, the great powers of Europe; hence, often, a superhuman agent; a spirit; a divinity.
2. (Science: psychology) The exertion of a strong influence or control over others in a variety of settings; administrative, social, academic, etc. Mental or moral ability to act; one of the faculties which are possessed by the mind or soul; as, the power of thinking, reasoning, judging, willing, fearing, hoping, etc.
3. (Science: mechanics) The rate at which mechanical energy is exerted or mechanical work performed, as by an engine or other machine, or an animal, working continuously; as, an engine of twenty horse power. Applied force; force producing motion or pressure; as, the power applied at one and of a lever to lift a weight at the other end.
4. (Science: unit) The english unit of power used most commonly is the horse power. See Horse power.
5. (Science: mathematics) The product arising from the multiplication of a number into itself; as, a square is the second power, and a cube is third power, of a number.
6. (Science: optics) The degree to which a lens, mirror, or any optical instrument, magnifies; in the telescope, and usually in the microscope, the number of times it multiplies, or augments, the apparent diameter of an object; sometimes, in microscopes, the number of times it multiplies the apparent surface.
7. Power may be predicated of inanimate agents, like the winds and waves, electricity and magnetism, gravitation, etc, or of animal and intelligent beings; and when predicated of these beings, it may indicate physical, mental, or moral ability or capacity.
8. (Science: geometry) Power of a point (relative to a given curve), the result of substituting the coordinates of any point in that expression which being put equal to zero forms the equation of the curve; as, x^2 – y^2 – 100 is the power of the point x, y, relative to the circle x^2 – y^2 – 100 = 0.
Origin: OE. Pouer, poer, OF. Poeir, pooir, F. Pouvoir, n. & v, fr. LL. Potere, for L. Posse, potesse, to be able, to have power. See Possible, Potent, and cf. Posse comitatus.