Based partly on the Latin iacere, "to throw", dejection means literally "cast down"—that is, "downcast". Like melancholy, gloom, and even sadness, dejection seems to have been declining in use for many years; instead, we now seem to prefer depression (whose roots mean basically "a pressing down"). Since depression is also the word used by doctors, lots of people now assume that anyone depressed should be taking an antidepressant; if we went back to dejected and dejection, we might not be so quick to make that assumption.