sailor's handkerchief
when you blow snot out of your nose onto the ground because you don't have a kleenex or hanky to use.
The cold air made my nose run, so I did a sailor's handkerchief on the street.
sailor's handkerchief
When you need to blow your nose but have no kleenex or handkerchief or anything else to blow in, so you just lean over a bit, compress one nostril, and let it fly out of the other nostril, onto the ground.
The cold air was making my nose run, so I did a sailor's handkerchief on the street.