Bog material is a type of soil composed of partially decomposed plant matter found in wetlands. The term 'bog material' is often used interchangeably with the term 'PEAT', which is a 4-letter word that is one of the solutions to this crossword puzzle. PEAT is formed when plants, such as sphagnum moss, are not fully decomposed due to the acidic and anaerobic conditions of the bog environment. PEAT is an important source of fuel and is also used in horticulture and gardening.