Frenchman or free man
Franciso is a rare spelling variant of Francisco, which is the Spanish and Portuguese form of the Latin name Franciscus. It originally denoted someone from France, but later became synonymous with the concept of freedom. This specific spelling is often considered a typographical variant or a rare phonetic adaptation of the more common Francisco.
Less common today
Franciso isn't in the latest US Top 1000. It last peaked at #4,310 in 1991.
US births per 5-year period, 1990βpresent (SSA data).