Cobarde means 'coward'. It's a powerful adjective used to describe someone who lacks the courage to do something difficult or unpleasant.
In this song, Bad Bunny sings, "Ya sé que soy un cobarde" (I already know I'm a coward). He uses this strong word to express his deep regret and self-awareness, admitting that he's running away from the relationship instead of facing the consequences of his actions.
Puerto Rican superstar Bad Bunny drops the tough front here and takes full blame for a trainwreck relationship. Right out of the gate, he calls himself a cabrón (a jerk / bastard) and admits he does not deserve forgiveness with "Que no merezco tu perdón" [That I don't deserve your forgiveness]. Instead of making excuses, he accepts that buying peace with "flores y los regalos" [flowers and gifts] is totally useless when you keep lying. He knows he ruined love for his ex, noticing that "por mí ahora eres peor / No quieres que más nadie te hable de amor" [because of me you are worse off now / You don't want anyone else talking to you about love].
His solution? Total retreat. He calls himself a coward ("Ya sé que soy un cobarde" [I already know I'm a coward]) and walks away before he can smash her heart into pieces one more time. The hook delivers the ultimate goodbye: "Te deseo lo mejor / Ojalá que te olvides de mí" [I wish you the best / I hope you forget about me]. If you want to pretend you never met him on the street ("haz que no me conoces" [act like you don't know me]), he is completely fine with that, as long as you find happiness far away from his mess.