When someone does something girlishly, they do it in a way people think of as “like a girl”: how they laugh, move, talk, or dress. It can be a plain description — a light laugh, a shy little gesture. Though actually it often carries a judgment too, as if that way of acting is too soft, too cute, or not serious enough. Older books used it more freely. Today some people are careful with it, because “like a girl” has long been used to put girls down, and boys as well if they are not “tough.” It can also describe a look: clothes or colours that feel made for a girl, in that old picture of girlhood. It is not a formal word.