Latin word quasi comes from Latin quam, Latin si (If, supposing that.)

Detailed word origin of quasi

Dictionary entry	Language	Definition
quam	Latin (lat)	(after comparative nouns) than. (in comparisons) as. In what (which) way, to what (which) degree; how, how much, as much as, as far as.
si	Latin (lat)	If, supposing that.
quasi	Latin (lat)	As (like). As if.

Words with the same origin as quasi