This has several meanings, one of them literal and the other one quite idiomatic. 1. To fill some clothing with soft material (padding) to make it thicker, warmer or protective. "This coat is really warm after I padded it out with an extra layer of wool." or "If the shoulders aren't the right shape we can pad them out a bit." 2. To fill some work (e.g. a piece of writing, radio, TV, a film) with unnecessary information in order to make it longer. "The student clearly had nothing to say in her essay so she just padded it out with irrelevant statistics" Leave comments and read transcriptions at http://teacherluke.co.uk/phrasal-verb-a-day/110-to-pad-out/