Prescription abbreviations are widely used by doctors.... Prescription abbreviations are widely used by doctors and they are in the form of Latin words. Here`s some medical abbreviations commonly used based on my professional nursing profession: WHEN TO TAKE MEDICINE: PC - Post Cibum in Latin which means After Meals. AC - Ante Cibum in Latin which means Before Meals. HS - Hora Somni in Latin which means At Bedtime.