The Compendium of Bheḷa 4.4.9

4.4.9

pācako nāma aśitapītalīḍhakhāditamāhārajātaṃ jātanīryaṃ pācayatīti[ - -ca] pācakaḥ | yaḥ svakaṃ kāmamevāgniṃ prapūrayati harṣayati ||

That called pācaka digests the mass of food that has been eaten, drunk, licked, and chewed, once its potency is released; hence it is [called] pācaka. It satisfies and delights its own fire according to its desire.