Definition of fly at:
(adj) :
having no variations in
altitude; deflated, especially because of a
puncture
"the land around here is flat."
(v) :
so as to be flat; bluntly
"spread the tablecloth flat over the table."
(n) :
a note played a
semitone lower than a
natural, denoted by the symbol
? sign placed after the letter representing the note (e.g., B?) or in front of the note symbol (e.g. ??); an
apartment
"she liked to walk in her flats more than in her high heels."