Question: I know the antonym of "to" is "from".

> 
> 1. He went to the station.
> 2. He came from the station.
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I am searching for a preposition opposite in meaning to "toward", but I could not find it, so I use "side" as follows:

> 
> 3. He went toward the station.
> 4. He came from the station side.
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> 
> 

Is there any preposition opposite in meaning to "toward"?

Answer: 
I'm not sure this qualifies as a preposition, but if your aim is to express only the person’s *direction* of travel, and not where they are traveling to or from, then you could change #4 to:

> 
> 4. He came from the direction of the station.
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> 
> 

Given that aim, however, note that #3 can also be read as suggesting more than just direction. Your "went toward” isn't as emphatic as "went to", but it does still hint at the station being the person's destination. If you want to make it clearer that they are merely traveling in that direction, then #3 might be better changed as well, to something like:

> 
> 3. He went in the direction of the station.
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> 
>
The opposite of *toward X* is usually *away from X*.

> 
> He went toward the station.
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> 

> 
> He went away from the station.
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This works with *come*:

> 
> He came toward the station side.
> 
> 
> 

> 
> He came away from the station side.
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> 
> 

Note that:

*X goes toward Y* and *X comes toward Y* will mean that at the end, X will be *closer* to Y but not necessarily *at* Y.

*X goes away from Y* and *X comes away from Y* will mean that at the end, X will be *further* from Y but not necessarily completely out of the sight of Y.