A noodle is a thin strip of pasta, usually cut or extruded from some kind of dough. It is the basic unit in dishes like spaghetti, linguine, soba, and udon. The term often refers to moist, cooked pasta, since it has connotations of curviness and slipperiness, but also to dried noodles that must be reconstituted by boiling or soaking in water.
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Noodling is playing semi-random, usually improvised, music. It usually happens in the middle of a rehearsal when the conductor is trying to say something important. Also called doodling.
The word "noodle" can also be used as a nickname for the brain.