adjective

1. urgent; pressing
2. soon to happen; imminent
3. without delay; immediate to demand instant obedience
4. designating a food or beverage in readily soluble, concentrated, or precooked form, that can be prepared quickly, as by adding water
5. Archaic present; current

Etymology: LME < MFr < L instans, prp. of instare, to stand upon or near, press < in-, in, upon + stare, to stand

adverb

1. Old Poet. at once; instantly
2. Old-fashioned (in the) present (month) yours of the 13th (day) instant received

noun

1. a point or very short space of time; moment
2. a particular moment