Is there a way to clear auto complete data?

I have a cell that is Validated as Add or Remove; however, when I
forst put the data list in I put "Add/Remove", instead of "Add,
Remove". I fixed it but it still rembers that i had used it in that
cell once. Now with auto complete on, When I enter "A" it wants to
complete to Add/Remove, instead of Add. ( This only happens the first
time, but it is still bother some. Is there a way to clear auto
complete?