what does digestion mean
â¢ DIGESTION (noun). The noun DIGESTION has 3 senses: 1. the process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat. 2. the organic process by which food is converted into substances that can be absorbed into the body. 3. learning and coming to understand ideas and information. Familiarity information: DIGESTION used as a noun is uncommon.