Formal:
* Clarify: To make something clear and understandable.
* Elucidate: To make something clear or easy to understand by explaining it.
* Illustrate: To make something clear by giving examples or using pictures.
* Expound: To explain something in detail.
* Articulate: To express something clearly and effectively.
Informal:
* Break down: To simplify something so it's easier to understand.
* Lay out: To explain something in a clear and organized way.
* Spell out: To explain something in detail, leaving nothing to be misunderstood.
* Make clear: To ensure something is understood.
* Show: To demonstrate something.
Other possibilities:
* Describe: To give an account of something.
* Define: To give the meaning of something.
* Interpret: To explain the meaning of something.
* Summarize: To give a brief explanation of something.
* Translate: To explain something in different words, especially in another language.
The best synonym will depend on the specific situation. Consider the context and what you are trying to achieve when choosing the most appropriate word.