 Visit StopTextStopRex.org. A message brought to you by the National Highway Traffic Safety Administration, Project Yellow Light, and the Ad Council. Stopped US Kids presents What to Expect When You're Expecting. A teenager learning the lingo. Jelly. Jelly adjective. Jelly is a shorter, better way to say jealous. As in, Chloe, I am like so jelly of your unicorn phone case.