1. According to need (physicians use PRN in writing prescriptions)
   - as needed, as required, PRN

Encyclopedia: Pro re nata

• presage
• presbyacusis
• presbycousis
• presbycusis
• presbyope
• presbyopia
• presbyopic
• presbyter
• presbyterate
• presbyterial
• Presbyterian
• Presbyterian Church
• Presbyterianism
• presbytery
• Presbytes
• Presbytes entellus
• preschool
• preschooler
• prescience
• prescient
• presciently
• prescind
• Prescott
• prescribe
• prescribed