1. Autumn
   Autumn (fall in North America) is one of the four temperate seasons, the transition between summer and winter..
   http: //academickids.com/encyclopedia/index.php/Aut...
   
   
2. Autumnal equinox
   In astronomy, the autumnal equinox signals the beginning of autumn in the northern hemisphere
   http: //academickids.com/encyclopedia/index.php/Aut...