Means to say its a long time (8)
I believe the answer is:
averages
'means' is the definition.
(mean is a type of average)
'its a long time' is the wordplay.
'its' becomes 'aver' (I can't justify this - if you can you should give a lot more credence to this answer).
'a long time' becomes 'ages' (ages can mean a very long time).
'aver'+'ages'='AVERAGES'
'to say' is the link.
Can you help me to learn more?
(Other definitions for averages that I've seen before include "Data included in cricket statistics" , "Evens out to" , "Means" , "estimations of mean" , "that are of great concern to cricketers" .)