- shelf - a support that consists of a horizontal surface for holding objects
--1 is a kind of support
--1 is a part of
--1 has particulars:bookcase; buffet, counter, sideboard; cabinet; closet; chest of drawers, chest, bureau, dresser; etagere; grocery store, grocery, food market, market bookshelf; hob; mantel, mantelpiece, mantle, mantlepiece, chimneypiece; overmantel - ledge, shelf - a projecting ridge on a mountain or submerged under water
--2 is a kind of ridge
--2 has particulars: berm - ledge, shelf - a projecting ridge on a mountain or submerged under water