NY garden mature, length as measured (7)
I believe the answer is:
yardage
'ny garden' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'mature length as measured' is the wordplay.
I cannot quite see how this works, but
'mature' could be 'age' (synonyms) and 'age' is found in the answer.
'length' could be 'yard' (I have seen 'A length ' mean 'yard' so perhaps 'length' could also mean 'yard') and 'yard' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for yardage that I've seen before include "Golf or American Football statistic" , "use of enclosed space" , "Gay dear (anag.)" , "What a caddy should know" , "Distance measured in imperial units" .)