The phrase "by reason of" means "because of" or "due to." There are many synonyms for this phrase, including "on account of," "as a result of," "owing to," "due to the fact that," and "thanks to." These synonyms can be used interchangeably with the phrase "by reason of" to convey the same meaning. "On grounds of," "based on," "in consequence of," and "by virtue of" are other synonyms that are more formal and are often used in legal or academic writing. Regardless of the synonym used, the phrase conveys a causal relationship between an action or event and the reason for it occurring.