An obvious attempt to discourage imitators (6)
I believe the answer is:
patent
'an obvious' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for patent that I've seen before include "evident" , "This leather has a glossy varnished surface" , "unmistakeable" , "Registration of ownership of invention" , "Like a medicine" .)