at once

once  (wns)

adv.

1. One time only: once a day.

2. At one time in the past; formerly.

3. At any time; ever: Once known, his face is never forgotten.

4. By one degree of relationship: my first cousin once removed.

n.

A single occurrence; one time: Once will have to do. You can go just this once.

conj.

As soon as; if ever; when: Once he goes, we can clean up.

adj.

Having been formerly; former: the once capital of the nation.

Idiom:

at once

1. All at one time; simultaneously: Everything happened at once. The view of the skyline is at once awesome, grand, and disappointing.

2. Immediately; instantly: Leave the room at once.

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[Middle English ones, from on, one, from Old English n; see oi-no- in Indo-European roots.]

Thesaurus

Adv.	1.	at once - 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!" forthwith, immediately, instantly, like a shot, right away, straight off, straightaway, directly, now
	2.	at once - simultaneously; "he took three cookies at a time" at a time, at one time