Females sailed up the creek (6)
I believe the answer is:
ladies
'females' is the definition.
(lady is a kind of female)
'sailed up the creek' is the wordplay.
'up the creek' is an anagram indicator.
'sailed' anagrammed gives 'LADIES'.
(Other definitions for ladies that I've seen before include "Ideals for gentlewomen" , "Public facility" , "Females" , "Well-mannered women" , "Convenience" .)