Mō'ment, n.

n. [Fr. & Pr. moment, It. & Sp. momento, Lat. momentum, for movimentum, from movere, to move.]

1. A minute portion of time; an instant. “In a moment, in the twinkling of an eye.” 1 Cor. xv. 52.
2. Impulsive power; force; momentum.

Touch, with lightest moment of impulse, His free will.              Milton. 3. Hence, importance in influence or effect; consequence; weight or value. It is an abstruse speculation, but also of far less moment to us than the others.              Bentley.

4. An essential element; a deciding point, fact, or consideration; essential or influential circumstance.
5. (Math.) An infinitesimal change in a varying quantity; an increment or decrement. [Obs.]
6. (Mech.) Tendency, or measure of tendency, to produce motion, especially motion about a fixed point or axis.

Moment of a couple, 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 line into the shortest distance between the line and the direction of this component. (c.) With respect to a plane, 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 products 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, &c. — Virtual moment. See VIRTUAL. Syn. — Instant; twinkling; consequence; weight; force; value; consideration; signification; avail. — MOMENT, INSTANT. A moment allows of a beginning and end; an instant is indivisible. The latter, therefore, expresses more brevity and urgency than the former. “Do it this instant,” requires the utmost haste. “Do it this moment,” admits of no hesitation or delay. The flighty purpose never is o'ertook Unless the deed go with it: from this moment The very firstlings of my heart shall be The firstlings of my hand.              Shak. This is not all: Patroclus, on the shore, Now pale and dead, shall succor Greece no more. Fly to the fleet, this instant fly, and tell The sad Achilles how his loved one fell.        Pope.