1. idiomatic expression an expression whose meanings cannot be inferred from the meanings of the words that make it up
  2. indirect expression an indirect way of expressing something
  3. atomic explosion the explosion of an atomic bomb
  4. image compression the compression of graphics for storage or transmission
  5. arithmetic progression (mathematics) a progression in which a constant is added to each term in order to obtain the next term
  6. expression the communication of your beliefs or opinions
  7. automatic data processing data processing by a computer
  8. slang expression informal language consisting of words and expressions that are not considered appropriate for formal occasions; often vituperative or vulgar
  9. parenthetical expression an expression in parentheses
  11. dysthymic depression mild chronic depression
  12. turn of expression a distinctive spoken or written expression
  13. manic depression a mental disorder characterized by episodes of mania and depression
  15. mathematical operation (mathematics) calculation by mathematical methods
  16. impression a vague idea in which some confidence is placed
  17. anaclitic depression severe and progressive depression in infants who lose their mother and do not get a suitable substitute
  18. endogenous depression a state of depression for which there is no apparent precipitating cause
  19. psychotic depression a state of depression so severe that the person loses contact with reality and suffers a variety of functional impairments
  20. facial expression a gesture executed with the facial muscles