najlon

1. nylon
   Ova jakna je od najlona, pa ne propušta vodu. — This jacket is made of nylon, so it's waterproof.
2. colloq. plastic sheeting; plastic bag
   Pokrij drva najlonom da ne pokisnu. — Cover the firewood with plastic so it doesn't get wet.
   Stavi sendviče u najlon. — Put the sandwiches in a plastic bag.

The phrase "najlon kesa" is the usual name for a plastic bag.