Unaware patent has line I inserted (9)
I believe the answer is:
oblivious
'unaware' is the definition.
('oblivious' can be similar in meaning to 'unaware')
'patent has line i inserted' is the wordplay.
'patent' becomes 'obvious' ('obvious' can be similar in meaning to 'patent'**).
'has' indicates putting letters inside.
'line' becomes 'l'.
'inserted' means one lot of letters goes inside another.
'obvious' enclosing 'l' is 'oblvious'.
'oblvious' placed around 'i' is 'OBLIVIOUS'.
(Other definitions for oblivious that I've seen before include "like Lethe?" , "Apt to forget" , "Heedless" , "Unconscious" , "Forgetful; unaware" .)