As a Noun:
1. A flat round covering to a container, such as a jar, that is fastened by being tightly twisted. English = screw-top, top, cap, lid.
2. A glass container with a screw-top that is used for storing food such as jam. English = jar.
As a Verb or Adjective:
1. To fasten or unfasten a screw-top on a jar.