1. A point in duration; a moment; a portion of time too short to be estimated; also, any particular moment.
There is scarce an instant between their flourishing and their not being.
Hooker. 2. A day of the present or current month; as, the sixth instant; — an elliptical expression equivalent to
the sixth of the month instant, i. e., the current month. See Instant, a., 3.
Syn. — Moment; flash; second.
Instantaneity
(In*stan`ta*ne"i*ty) n. [Cf. F. instantanéité.] Quality of being instantaneous. Shenstone.
Instantaneous
(In`stan*ta"ne*ous) a. [Cf. F. instantané.]
1. Done or occurring in an instant, or without any perceptible duration of time; as, the passage of electricity
appears to be instantaneous.
His reason saw
With instantaneous view, the truth of things.
Thomson. 2. At or during a given instant; as, instantaneous acceleration, velocity, etc.
Instantaneous center of rotation (Kinematics), in a plane or in a plane figure which has motions both
of translation and of rotation in the plane, is the point which for the instant is at rest. — Instantaneous
axis of rotation (Kinematics), in a body which has motions both of translation and rotation, is a line,
which is supposed to be rigidly united with the body, and which for the instant is at rest. The motion of
the body is for the instant simply that of rotation about the instantaneous axis.
— In`stan*ta"ne*ous*ly, adv. — In`stan*ta"ne*ous*ness, n.
