suber

Disputed. According to one hypothesis, it is from the same Proto-Indo-European root as Old High German swigen (“to be silent”) and its West Germanic cognates, possibly a reference to cork being stripped without harming the tree. However, an Indo-European etymology for the Germanic set is disputed; see *swīgā. Alternatively, it may be connected with Ancient Greek σῦφαρ (sûphar, “wrinkled skin”), from a third, perhaps substrate source, with an approximate form *sūbʰ-.