So Definition

adverb
To the degree expressed or understood; to such an extent.
Why are you so late?
Webster's New World
To a very high degree; very.
They are so happy.
Webster's New World
To an unspecified but limited degree, amount, number, etc.
To go so far and no further.
Webster's New World
Afterward; then.
To the gas station and so home.
American Heritage
Used to preface a remark or signal a new subject.
So what happened here? So I'm going to the store to buy some milk.
American Heritage
Synonyms:
adjective
True; in reality.
Is that so?
Webster's New World
In good order.
Everything on his desk must be exactly so.
American Heritage
conjuntion
For that reason; therefore.
This is the easiest way to get there, so don't argue.
American Heritage
In order that; with the purpose that.
Talk louder so (that) everyone can hear.
Webster's New World
With the result that; because of this.
She smiled, so I did too.
Webster's New World
If only; as long as; provided (that)
Webster's New World
Synonyms:
pronoun
Such as has already been suggested or specified; the same or roughly the same.
She became a loyal friend and remained so.
American Heritage
That which has been specified or named.
They are friends and will remain so.
Webster's New World

A Mon-Khmer-speaking people of Laos and Thailand.

Wiktionary
interjection
Used to express surprise, approval or disapproval, triumph, etc.
Webster's New World
abbreviation
Seller's option.
American Heritage
Shootout.
American Heritage
South.
Webster's New World
Significant other.
American Heritage
Strikeout(s)
Webster's New World
noun
Webster's New World
Synonyms:
symbol
The molecular formula for sulfur dioxide.
Wiktionary

Origin of So

  • Middle English from Old English swā swo- in Indo-European roots

    From American Heritage Dictionary of the English Language, 5th Edition