Entry 1 sense Webster, 1913 Ingestion /ĭnˌ-jĕs'-chən/ · In·ges·tion · IPA /ɪnˈd͡ʒɛst͡ʃən/ 01 n. The act of taking or putting into the stomach; as, the ingestion of milk or other food. 1. The act of taking or putting into the stomach; as, the ingestion of milk or other food.(Physiol.)