/ˌsɪnəˈpeɪt/ or /ˌsɪnəˈpeɪt/ is not found, but sinapate is a surname and likely means related to sinapism or mustard plasters

Definitions

1. noun

A mustard plaster, especially one applied to the chest to relieve congestion or coughing, in traditional medicine

“She applied a sinapate to her mother’s chest to help with the persistent cough.”