The name Sancho (Spanish: [ˈsantʃo]) is an Iberian name of Basque origin (Santxo, Santzo, Santso, Antzo, Sans).
[2] Feminine forms of the name are Sancha, Sancia, and Sanchia (Spanish: [ˈsantʃa]), and the common patronymic is Sánchez and Sanches.
Outside the Spanish-speaking world, the name is especially associated with the literary character Sancho Panza.
Sancho is a common slang term in the Spanish speaking world for the other man in the relationship.
As in a spouse or girlfriend who is being unfaithful with a Sancho.