to be happy that you will not have to deal with or see sb / sth again because you do not like them or it
be glad, etc. to see the back of sb / sth
to be happy that you will not have to deal with or see sb / sth again because you do not like them or it
Was I pleased to see the back of her!
Definiciones del Oxford Advanced Learner's Dictionary, 9.ª edición