Public road learner's used in practice, apparently (9)
I believe the answer is:
outwardly
'apparently' is the definition.
(thesaurus)
'public road learner's used in practice' is the wordplay.
'public' becomes 'out' (out can mean released to the public).
'road' becomes 'rd' (abbreviation).
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'used in' is an insertion indicator.
'practice' becomes 'way'.
'rd'+'l'='rdl'
'rdl' going into 'way' is 'wardly'.
'out'+'wardly'='OUTWARDLY'
(Other definitions for outwardly that I've seen before include "On the face of it" , "Externally" , "Superficially" , "As far as appearances are concerned" .)