play at something phrasal verb ( see also ↑ play )
1 . What is somebody playing at? British English spoken used when you do not understand what someone is doing or why they are doing it, and you are surprised or annoyed:
What do you think you’re playing at?
2 . if you play at doing something, you do not do it properly or seriously
play at doing something
He’s still playing at being an artist.
3 . British English if children play at doctors, soldiers etc, they pretend to be doctors, soldiers etc
play at being something
a 14-year-old playing at being a grown woman