Facilities left cast aside (6)
I believe the answer is:
ladies
'facilities' is the definition.
Although both the answer and definition are plural nouns, I don't see how one could define the other.
'left cast aside' is the wordplay.
'left' becomes 'l' (common abbreviation).
'cast' is an anagram indicator (letters are dispersed or cast around).
'aside' anagrammed gives 'adies'.
'l'+'adies'='LADIES'
Can you help me to learn more?
(Other definitions for ladies that I've seen before include "Lords' wives" , "Females" , "...... and gentlemen" , "Public facility" , "Convenience" .)