Females of unusual ideals (6)
I believe the answer is:
ladies
'females' is the definition.
(lady is a kind of female)
'unusual ideals' is the wordplay.
'unusual' indicates an anagram.
'ideals' anagrammed gives 'LADIES'.
'of' acts as a link.
(Other definitions for ladies that I've seen before include "9th" , "Well-mannered women" , "...... and gentlemen" , "Ideals for genteel women" , "Convenience" .)