Require old court to accept training (6)
I believe the answer is:
expect
'require' is the definition.
(I know that require can be written as expect)
'old court to accept training' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'court' becomes 'ct' (abbreviation used in road names).
'to accept' is an insertion indicator.
'training' becomes 'PE' (Physical Education).
'ex'+'ct'='exct'
'exct' enclosing 'pe' is 'EXPECT'.
(Other definitions for expect that I've seen before include "Regard as likely, suppose" , "Hope - await" , "Think of as likely to happen" , "Forecast" , "Regard something as probable" .)