1. With little or no preparation or forethought
   "an extempore skit";
   - ad-lib, extemporaneous, extemporary, impromptu, offhand, offhanded, off-the-cuff, unrehearsed

1. Without prior preparation
   "He delivered the speech extempore, impressing everyone with his quick thinking";
   - extemporaneously, extemporarily

1. Without previous consideration
   "I don't know the figures ex tempore";
   - off-hand [informal]

See also: ill-prepared, unprepared

Encyclopedia: Extempore