What is "gully hole"

Gully \Gul"ly\, n.; pl. Gullies. [Formerly gullet.]

1. A channel or hollow worn in the earth by a current of water; a short deep portion of a torrent's bed when dry.

2. A grooved iron rail or tram plate. [Eng.]

   Gully gut, a glutton. [Obs.]
   --Chapman.

   Gully hole, the opening through which gutters discharge surface water.