In the national anthem, what does the phrase "Mas si osare un extraño enemigo"…

This line comes from the first stanza of the Mexican national anthem: “Mas si osare un extraño enemigo profanar con su planta tu suelo” — but if a foreign enemy should dare to profane your soil with his footstep. The verb “osar” is an old-fashioned word meaning “to dare”, which is why the phrase confuses many people today.

In fact, generations of Mexican schoolchildren have misheard “Mas si osare” as “Masiosare”, jokingly imagining it as the name of a mysterious enemy. The anthem’s lyrics were written by Francisco González Bocanegra in 1853.