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.
Synonym: moment, flash, second.
Origin: f. Instant, fr. L. Instans standing by, being near, present. See instant.