The word "外嫁" is formed by directly combining the character "外" (wài), meaning "outside" or "foreign", with the character "嫁" (jià), which means "to marry" in the context of a woman marrying a man. This creates a compound where "外" modifies "嫁" to specify the act of marrying outside one's own cultural or national group, resulting in a term that denotes a woman marrying a foreigner.