Approbation des Lois

What does Approbation des Lois mean in American Law?

The definition of Approbation des Lois in the law of the United States, as defined by the lexicographer Arthur Leff in his legal dictionary is:

The Law French short-form title of a book which purports to set out the laws and customs of the island of Guernsey (one of the Channel Islands) as they were in 1580.