"No matter" is a common phrase used when referring to something that is not affected by a certain situation or condition. It is often used to indicate that something is certain despite any variables. Some synonyms for this phrase include "regardless," "irrespective," "even if," "despite," and "in spite of." These words can be used interchangeably depending on the context of the sentence. For example, "No matter what the weather is like, I'll still go for a run" could be written as "Regardless of the weather, I'll still go for a run" or "Even if it's raining, I'll still go for a run." By using synonyms for "no matter," you can add variety and clarity to your writing or speech.