Inimitably means in that “nobody can copy this as well” way. You put it with a verb, or with another describing word: she sings inimitably; he is inimitably funny. Same praise as inimitable, just telling you how it is done. It is a little playful and a little formal. You will not hear it much in the street, but writers like it when they want to say this could only be them. Though actually, it is not a fancy way to say very. Save it for a style or skill that is that person's, done that well.