2. also one of three answers you give your French teacher when he/she asks you a question that you don't know the answer too or are just too lazy to answer. (the others being "oui" and "non")
Student: "Ehh...je ne sais pas...mais c'était très intèressant?"
("What happened in the chapters that you read yesterday?" "Eh...I don't know...but it was very interesting?")