legible
Clear enough to read easily.
Legible means clear and easy to read. When your handwriting is legible, other people can understand what you've written without squinting, guessing, or asking you to rewrite it. A legible signature on a birthday card lets the recipient know exactly who it's from. A doctor's legible prescription helps the pharmacist give you the right medicine.
The opposite of legible is illegible, which means so messy or unclear that it can't be read. If you scribble your homework answers in a rush, your teacher might hand it back and ask you to make them more legible. Old documents sometimes become illegible when the ink fades or the paper deteriorates over time.
Legibility matters because writing exists to communicate. Even brilliant ideas lose their value if nobody can read them.