1. [n]  processing a photosensitive material in order to make an image visible; "the development and printing of his pictures took only two hours"
2. [adj]  relating to societies in which capital needed to industrialize is in short supply
3. [adj]  gradually unfolding or growing (especially as of something latent); "his developing social conscience"; "after the long winter they took joy in the developing warmth of spring"
4. [adj]  making or becoming visible through or as if through the action of a chemical agent; "he watched as the developing photograph became clearer and sharper"

DEVELOPING is a 10 letter word that starts with D.