The spelling of the word "dinner pad" is straightforward. The first syllable, "din", is pronounced /dɪn/ with a short "i" sound followed by an "n" sound. The second syllable, "ner", is pronounced /nər/ with a schwa sound followed by an "r" sound. The final syllable, "pad", is pronounced /pæd/ with a short "a" sound followed by a "d" sound. Together, the word is pronounced /ˈdɪn.ər.pæd/ with the stress on the first syllable. A dinner pad could be a pad of paper used to plan dinner or a cushion to sit on during dinner.
A pad of moderate thickness placed over the pit of the stomach before the application of a plaster jacket; after the plaster has set the pad is removed, leaving space for varying conditions of abdominal distention.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.