To quickly dress oneself in an article of clothing. A noun or pronoun can be used between "fling" and "on." A: "But I'm in my pajamas!" B: "Oh, just fling on any old thing and come meet us at the bar!" When I saw our dog slip through the fence, I flung on my coat and ran outside in my slippers to catch him.
fling something on oneselfand fling something on
to put an article of clothing onto oneself hastily. She got up and flung on her robe. She flung her robe on and went to answer the door.