The phrase "a friend repeatedly" is correct and usable in written English.
It can be used when describing an action or behavior that a friend does on multiple occasions.
Example: "She called me a friend repeatedly, emphasizing how much she valued our relationship."
Alternatives: "a friend over and over" or "a friend time and again".
In the Slenderman case, two 12-year-old girls allegedly stabbed their friend repeatedly in an attempt to murder her.
Villano, who referred to developing a criminal informant as "getting married," came to regard Scarpa as "a friend," and repeatedly bent, or even broke, the law on his behalf.
Let's get this out of the way right up front: I feel like a guy who's continually making excuses for a friend who repeatedly messes up.
For example, if you have a friend who repeatedly cancels plans with you at the last minute, tell her how you feel and then invite her to share her experiences with you: "When we make plans and you cancel at the last minute, I feel frustrated because it's too late to make other plans for myself.
A patient of mine recently described drowning in some digital quicksand after an argument with her friend: The day after their fight, the friend repeatedly instant messaged.
Surveillance footage shows the man attacking Usama and his friend, repeatedly punching and pushing them.
"You gotta relax your leg muscles," says my friend, repeatedly, as he demonstrates the position.
In fact, during the week preceding the move, I asked my friend repeatedly if she was certain that the missions group was actually coming to help.
("Not the Ukraine," says my ex-boyfriend's best friend, repeatedly, at parties, whenever I'm at the peak of my rhetorical powers, explaining just how the internet age has allowed my father to marry a woman my age trapped in Ukraine without a passport).
Ask your friend repeatedly if you can do homework together.
