understory

noun2

1. •
   [before a noun] The (layer of) plants that grow in the shade of the canopy of a forest above the forest floor.

   • In order to further narrow down the field of formation types reference is now made to the type of understorey that is found beneath the crowns or canopies of the dominant plants. — 1994
2. •
   (old-fashioned) A story of a building below the stories generally used for residence or work.

   • On the Vnder Story, tovvards the Garden, Let it be turned to a Grotta, or Place of Shade, or Estiuation. — 1625