What does the name Jessica-Amy mean?

Jessica first appeared in this form by Shakespeare, where he used it in his play 'The Merchant of Venice'; it belonged to the daughter of Shylock.

It is very likely that Shakespeare originally based it on the Biblical feminine name Iscah (which would have been spelled Jescha, in his time.)

Iscah comes from the Hebrew Yiskah-- meaning "To Behold."

Amy is the English form of the Old French name Amée, known to mean "Beloved." It is a vernacular form of the Latin Amata.