SOSA and SOZA are respellings of the Portuguese surname Sousa. This lineage is traced to a Spanish Basque baptismal title "Sus" meaning "fire-guardian."
This unusual designation referred to a citizen appointed to tend sacred pagan fires in a pre-Christian temple. Fire was a symbol of spiritual light. The Sousas or De Souzas were among high Portuguese nobility. Their coat of arms has three red diagonal stripes across a gold shield.
Source: Newspaper clipping regarding inquiring by Mrs. Maria Moreno Soza Gonzales, c. 1973, written to LaReina Rule at Southland Magazine, 604 Pine Ave., Long Beach, California, for origin, meaning and brief genealogy.