A "flowy shirt" refers to a loose-fitting and airy type of clothing, usually made from lightweight materials that allow it to move and drape gracefully. Full definition
I did flowy shirts with blazers or long cardigans, now that it's cooler a scarf would be good too. (corporettemoms.com)
I love your suggestion of a striped flowy shirt, but what about for those of us who are * ahem * a bit more conservative when it comes to matching florals and stripes? (kendieveryday.com)
Anyway, because we've been experiencing a big heat wave (typical since it is summer and we're still in a bad drought) I wore a really lightweight and flowy shirt which you can find here for under $ 50! (beautyandcolour.com)