To decode is to take out of code and put into understandable language. (Its opposite is encode, "to put into coded form".) But dreams may sometimes also be decoded; psychologists often try to decode the images of their patients' dreams so as to understand the emotions behind them. And readers must often decode what a novel or story or poem is telling them, which may require two or three readings. Decipher is often a synonym, though we now use it when talking about reading difficult handwriting.