"On a whim" is a neutral phrase: not positive or negative, and neither very formal nor very casual.

I don't think 'going off/out on a whim' is a phrase, but it's easy enough to imagine people saying it or thinking it might be.

Neither of the dictionaries don't say that.

See the whole list below. Very nice found.

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it.

. suddenly. If someone goes out on a limb, they do something they strongly believe in even though it is risky or extreme, and is likely to fail or be criticized by.

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[count] : a sudden wish, desire, decision, etc. When you have a small, temporary feeling of wanting to do something, it's called a "whim". .

unexpectedly. On kind of a whim Friday night, I made polvorones, or Mexican Wedding Cakes, for the next night's bachelorette party.

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unexpectedly.

On a whim I added some maraschino liqueur and a few dashes of orange bitters to the Auchentoshan, stirred the drink over ice, and sampled it. .

. ] y mañana castiga eso mismo o que perdona.

: a large capstan that is made with one or more radiating arms to which a horse may be yoked and that is used in mines for raising ore or water.
For some reason or another, your husband is not invested in this marriage.
Couples who get back together have resolved within themselves that they’re really going to make an effort this time.

Go out on a limb definition: to do something risky or extreme , which puts you in a position of weakness | Meaning, pronunciation, translations and examples.

whim.

the two words together almost choke me. Whim definition: A whim is a wish to do or have something which seems to have no serious reason or purpose. .

Out of a whim meaning. Clearly that construction was inspired by “out on a limb. . . quit his job on a whim.

Amazing selection of Japanese seed beads and Delicas.

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fms.

Whim definition: A whim is a wish to do or have something which seems to have no serious reason or purpose.

Two words put together to create a whole new meaning.

at the drop of a hat.

unexpectedly.