Some American next to Princess, Frank? (4)
I believe the answer is:
anne
'princess frank?' is the definition.
'Anne' can be an answer for 'frank?' (Anne Frank, Holocaust victim). I'm not sure about the 'princess' bit.
'some american next to' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'ANNE' is hidden in the letters of 'american next to'.
(Other definitions for anne that I've seen before include "Second or fourth wife of Henry VIII" , "One of two Henry VIII wives" , "First queen of Great Britain and Ireland" , "One of the Bronte sisters" , "- of Green Gables (children's classic)" .)