A page worked in practical (7)
I believe the answer is:
applied
'practical' is the definition.
(similar in meaning)
'a page worked in' is the wordplay.
'page' becomes 'p'.
'worked' becomes 'plied' (to ply is to work with a tool).
'in' indicates putting letters inside.
'p' going into 'plied' is 'pplied'.
'a'+'pplied'='APPLIED'
(Other definitions for applied that I've seen before include "Went for university place" , "Type of science" , "put to practical use" , "Practical rather than theoretical" , "Asked (for job); not pure (maths)" .)