scribble

/ˈskrɪbəl/
noun
  1. Careless or messy writing or drawing.
    • I couldn't read his scribble on the sticky note.
    • The margins of the book were filled with scribble.
    • She turned in a page of scribble instead of a proper essay.
verb
  1. To write or draw something quickly or carelessly, often in a way that is hard to read.
    • During the lecture, she scribbled notes in the margins of her notebook.
    • The child scribbled all over the paper with a purple crayon.
    • I scribbled down the phone number before I forgot it.