| Noun | 1. | digestion - the process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat | |
| 2. | digestion - the organic process by which food is converted into substances that can be absorbed into the bodygastric digestion - the process of breaking down proteins by the action of the gastric juice in the stomach | |
| 3. | digestion - learning and coming to understand ideas and information; "his appetite for facts was better than his digestion"learning, acquisition - the cognitive process of acquiring skill or knowledge; "the child's acquisition of language" | |