mortgage-backed security: a security created when a group of mortgages are gathered together and bonds are sold to other institutions or the public; investors receive a portion of the interest payments on the mortgages as well as the principal payments; usually guaranteed by the government
standing wave: a wave (as a sound wave in a chamber or an electromagnetic wave in a transmission line) in which the ratio of its instantaneous amplitude at one point to that at any other point does not vary with time