devanar

To wind thread, yarn, wire, or cable onto a spool or reel — devanar un ovillo de lana. Its main claim to fame in everyday Spanish is the fixed idiom devanarse los sesos ("to rack one's brain"), which is far more common than the literal winding sense.

• Mi abuela devanaba la lana antes de empezar a tejer. — My grandmother wound the yarn before starting to knit.
• Me devané los sesos tratando de resolver ese acertijo. — I racked my brain trying to solve that riddle.
• El electricista devanó el cable con cuidado. — The electrician wound the cable carefully.

Not recognizing devanarse los sesos as a fixed idiom — learners sometimes try to translate it literally instead of recognizing it means "to think hard/rack one's brain," unrelated to actual thread.

• expression Devanarse los sesos — A well-established Spanish idiom meaning to rack one's brain over something, first attested in the Corpus Diacrónico del Español (CORDE) from the late 18th century — it compares intense thinking to winding thread around a spool.