Private try-out on a regular basis? Nonsense (8)
I believe the answer is:
tommyrot
'nonsense' is the definition.
(I've seen this before)
'private try-out on a regular basis?' is the wordplay.
'private' becomes 'tommy'.
'on a regular basis?' means one should take alternating letters.
'try'+'out'='tryout'
The alternate letters of 'tryout' are 'rot'.
'tommy'+'rot'='TOMMYROT'
(Other definitions for tommyrot that I've seen before include "Slangy nonsense from Thomas?" , "Poppycock" , "Balderdash, bilge" , "Stuff and nonsense, baloney" , "Absolute rubbish, nonsense" .)