General expansion:
* Enlarge: Increase in size or scope.
* Extend: Make something longer or wider.
* Widen: Make something broader or more comprehensive.
* Grow: Increase in size or number.
* Develop: Become larger or more complex.
* Amplify: Make something louder or stronger.
Specific expansion:
* Inflate: Increase in volume or size, usually by filling with air or gas.
* Dilate: Make something wider or larger in diameter.
* Proliferate: Increase rapidly in number.
* Spread: Extend over a larger area.
* Branch out: Expand into new areas or activities.
Figurative expansion:
* Elaborate: Give more details or explanation.
* Clarify: Make something clearer or easier to understand.
* Explain: Provide a detailed account of something.
The best synonym to use will depend on the specific context and the meaning you want to convey.