1、study of the earth's surface; includes people's responses to topography and climate and soil and vegetation; 2、the aggregate of past events; 3、not easy; requiring great physical or mental effort to accomplish or comprehend or endure; 4、some situation or event that is thought about; 5、arousing or holding the attention; 6、any day except Sunday (and sometimes except Saturday); 7、some abrupt occurrence that interrupts an ongoing activity; 8、actively or fully engaged or occupied; 9、a unit of time equal to 60 seconds or 1/60th of an hour.