pill. n. 1. (Pharmacology) a small spherical or ovoid mass of a medicinal substance, intended to be swallowed whole. 2. (Medicine) the pill (sometimes capital) an oral contraceptive. 3. something unpleasant that must be endured (esp in the phrase bitter pill to swallow). 4. a ball or disc. 5. a small ball of matted fibres that forms on the surface of a fabric through rubbing.
Fill your jars, while still hot place a waxed disc over the pickle, then a clear (cellophane) circle over the top of the jar, and secure with a rubber band. As anything with vinegar can get through the clear top it's best to put a metal lid as well, over the clear cover.
Then fit the metal screw band over the flat lid. Follow the manufacturer's guidelines enclosed with or on the box for tightening the jar lids properly. Do not retighten lids after processing jars. As jars cool, the contents in the jar contract, pulling the self-sealing lid firmly against the jar to form a high vacuum.