The Collaborative International Dictionary of English v.0.48:

Moment \Mo"ment\, n. [F. moment, L. momentum, for movimentum movement, motion, moment, fr. movere to move. See Move, and cf. Momentum, Movement.] 1. A minute portion of time; a point of time; an instant; as, at that very moment. [1913 Webster] In a moment, in the twinkling of an eye. --1 Cor. xv. 52. [1913 Webster] 2. Impulsive power; force; momentum. [1913 Webster] The moments or quantities of motion in bodies. --Berkley. [1913 Webster] Touch, with lightest moment of impulse, His free will. --Milton. [1913 Webster] 3. Importance, as in influence or effect; consequence; weight or value; consideration. [1913 Webster] Matters of great moment. --Shak. [1913 Webster] It is an abstruse speculation, but also of far less moment and consequence of us than the others. --Bentley. [1913 Webster] 4. An essential element; a deciding point, fact, or consideration; an essential or influential circumstance. [1913 Webster] 5. (Math.) An infinitesimal change in a varying quantity; an increment or decrement. [Obs.] [1913 Webster] 6. (Mech.) Tendency, or measure of tendency, to produce motion, esp. motion about a fixed point or axis. [1913 Webster] Moment of a couple (Mech.), the product of either of its forces into the perpendicular distance between them. Moment of a force. (Mech.) (a) With respect to a point, the product of the intensity of the force into the perpendicular distance from the point to the line of direction of the force. (b) With respect to a line, the product of that component of the force which is perpendicular to the plane passing through the line and the point of application of the force, into the shortest distance between the line and this point. (c) With respect to a plane that is parallel to the force, the product of the force into the perpendicular distance of its point of application from the plane. Moment of inertia, of a rotating body, the sum of the mass of each particle of matter of the body into the square of its distance from the axis of rotation; -- called also moment of rotation and moment of the mass. Statical moment, the product of a force into its leverage; the same as moment of a force with respect to a point, line, etc. Virtual moment. See under Virtual. [1913 Webster] Syn: Instant; twinkling; consequence; weight; force; value; consideration; signification; avail. [1913 Webster]The Collaborative International Dictionary of English v.0.48:

Rotation \Ro*ta"tion\, n. [L. rotatio: cf. F. rotation.] 1. The act of turning, as a wheel or a solid body on its axis, as distinguished from the progressive motion of a revolving round another body or a distant point; thus, the daily turning of the earth on its axis is a rotation; its annual motion round the sun is a revolution. [1913 Webster] 2. Any return or succesion in a series. [1913 Webster] Moment of rotation. See Moment of inertia, under Moment. Rotation in office, the practice of changing public officers at frequent intervals by discharges and substitutions. Rotation of crops, the practices of cultivating an orderly succession of different crops on the same land. [1913 Webster]