the.com/noodle

means A long, thin strip or tube of cooked dough, and — in slang — the human head or the act of improvising idly on an instrument or idea.

from The food sense comes from German 'Nudel,' which appeared in German in the 1600s-1700s from origins that are genuinely murky — possibly linked to Latin 'nodus' (knot), given how pasta twists and tangles. The slang sense of 'noodle' meaning 'head' arose in English in the 1700s, likely just riffing on the food's shape — a head as a soft, bendable thing atop the body. From there 'noodle around' or 'noodle on it' — meaning to tinker or think loosely — followed naturally, as if the brain itself were being lightly boiled.