General:
* Condense: To make something smaller or more concentrated.
* Shrink: To make something smaller in size.
* Reduce: To make something smaller or less in amount.
* Tighten: To make something more compact or firm.
* Squeeze: To press something firmly, especially to reduce its size.
For data:
* Zip: To compress a file to make it smaller.
* Archive: To compress and store files in a single container.
For physical objects:
* Press: To apply pressure to something.
* Pack: To arrange things tightly together.
* Fold: To bend something over itself.
For information:
* Summarize: To give a brief overview of something.
* Abbreviate: To shorten something.
* Concise: To make something brief and to the point.
The best synonym to use will depend on the specific situation.