Every six hours, on a prescription

• Four times a day, in prescriptions
• Rx abbr.
• Four times daily, in an Rx
• Every six hours, in an Rx
• Four times a day: Abbr.
• Four times a day, on an Rx
• Prescription abbr
• Rx abbr

Wikipedia Word definitions in Wikipedia
QID is an acronym and may refer to: Quater}} in die (q.i.d.), a medical abbreviation meaning "four times each day" Queen's Indian Defense , a chess opening