The SI unit of mass is the kilogram. So the answer might be KILO.
It's hard to say about the other two without knowing the given letters. But. I would have thought that fancy dress is two words, phrenologist fits the clue though.
You're taking the piss Harry. How was I supposed to know that your "fancy dress" was built on ?A?C???ESS. (if indeed it was). If you had told us the given letters,as any sensible person would have,you would have got the answer much sooner. Think about it Harry. How was anybody supposed to deduce which letters of "fancy dress" were crossing ones. You utter prick.