Nine out of sixty pigs live here (3)
I believe the answer is:
sty
'pigs live here' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'nine out of sixty' is the wordplay.
'nine' becomes 'IX' (roman numeral).
'out of' is a deletion indicator.
'sixty' with 'ix' taken out is 'STY'.
Can you help me to learn more?
(Other definitions for sty that I've seen before include "Eye ailment or pig's home" , "Animal pen" , "Porcine pen" , "Pig pen" , "Enclosure for swine" .)