the form of Old French written in England from the Norman Conquest (1066) through the Middle Ages; the administrative and legal language of England 12c.-17c.; the name is attested from 1887 and was popularized, if not coined, by Skeat.
And Frenssh she spak ful faire and fetisly,
After the scole of Stratford-atte-Bowe,
For Frenssh of Parys was to hir unknowe.