Test learner in gym class, for instance (7)
I believe the answer is:
example
'instance' is the definition.
('example' can be a synonym of 'instance')
'test learner in gym class' is the wordplay.
'test' becomes 'exam' ('exam' can be a synonym of 'test'**).
'learner' becomes 'l'.
'in' is an insertion indicator.
'gym class' becomes 'pe' (abbreviation for physical education).
'l' put into 'pe' is 'ple'.
'exam'+'ple'='EXAMPLE'
'for' acts as a link.
(Other definitions for example that I've seen before include "Specimen, sample" , "Standard" , "Instance or illustration" , "Prototype" , "Fact that illustrates a general rule" .)