Listeners, having started young, have plenty of time (5)
I believe the answer is:
years
'listeners' is the definition.
Although both the answer and definition are plural nouns, I don't understand how one could define the other.
'started young have plenty of time' is the wordplay.
'started' suggests taking the first letters.
'have' means one lot of letters go next to another.
'plenty of time' becomes 'ears' (I can't explain this - if you can you should give a lot more credence to this answer).
The initial letter of 'young' is 'y'.
'y'+'ears'='YEARS'
'having' acts as a link.
Can you help me to learn more?
(Other definitions for years that I've seen before include "12 month periods" , "Very long time (colloq.)" , "Units of time" , "Periods of time" , "Long periods" .)