What is meant by the prefix Ui in front of an irish surname?

Question

Was just wondering if someone knew what the prefix Ui meant and what context you would use it in when its in front of an irish surname eg Ui Cearbhaill

Answer 1

Alpha is right.  It's used when it's someone's wife, it does not mean "descendant of".  The female version of "Ó" is "Ní", not "Uí".

Answer 2

(Uí) in front of the surname of a female means -Mrs.- as in; Máire Bean Uí Cearbhaill which translates to Mrs. Mary Carroll or (O'Carroll)

Irish

Answer 3

It means "descendant of". The  "O'" that is used in Irish surnames today is the same as "Ui". The modern form of this name is O'Carroll.