The term "US-Mexican" is a modern compound adjective formed by combining the abbreviation for the United States with the demonym for Mexico, linked by a hyphen. This hyphenated structure is a common and efficient method in English for creating attributive adjectives that denote a bilateral relationship, connection, or comparison between two distinct national entities. The logic is purely syntactic and geopolitical, directly combining the identifiers of the two nations to specify a context—such as relations, trade, or culture—that involves both. Unlike words with deep classical roots, its formation follows contemporary English compounding conventions for clarity and specificity in international discourse.

Structure: US (country name) + - (hyphen) + Mexican (demonym) - US: An abbreviation for "United States," a country name. - -: A hyphen, a punctuation mark used to join words. - Mexican: A demonym (from Latin Mexicanus, from Mexico, the name of the country) meaning "of or relating to Mexico."