INSTANTLY

instantaneously, outright, instantly, in a flash

(adverb) without any delay; “he was killed outright”

immediately, instantly, straightaway, straight off, directly, now, right away, at once, forthwith, like a shot

(adverb) without delay or hesitation; with no time intervening; “he answered immediately”; “found an answer straightaway”; “an official accused of dishonesty should be suspended forthwith”; “Come here now!”

Source: WordNet® 3.1

Etymology

Adverb

instantly (not comparable)

At once; without delay. [from 16th c.]

(archaic) Urgently; with insistence. [from 15th c.]

(obsolete) At the same time.

Synonyms

• (at once; without delay): immediately, instantaneously

Source: Wiktionary

In"stant*ly, adv.

1. Without the least delay or interval; at once; immediately. Macaulay.

2. With urgency or importunity; earnestly; pressingly. "They besought him instantly." Luke vii. 4.

Syn.

– Directly; immediately; at once. See Directly.

INSTANT

In"stant, a. Etym: [L. instans, -antis, p. pr. of instare to stand upon, to press upon; pref. in- in, on + stare to stand: cf. F. in. See Stand.]

1. Pressing; urgent; importunate; earnest. Rejoicing in hope; patient in tribulation; continuing instant in prayer. Rom. xii. 12. I am beginning to be very instant for some sort of occupation. Carlyle.

2. Closely pressing or impending in respect to time; not deferred; immediate; without delay. Impending death is thine, and instant doom. Prior.

3. Present; current. The instant time is always the fittest time. Fuller.

Note: The word in this sense is now used only in dates, to indicate the current month; as, the tenth of July instant.

In"stant, adv.

Definition: Instantly. [Poetic] Instant he flew with hospitable haste. Pope.

In"stant, n. Etym: [F. instant, fr. L. instans standing by, being near, present. See Instant, a.]

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.

Source: Webster’s Unabridged Dictionary 1913 Edition