1. Not wrinkled or creased
   - unwrinkled

See also: unfurrowed

• Protium
• Protium guianense
• Protium heptaphyllum
• proto
• Proto-Indo European
• Proto-Norse
• proto-oncogene
• protoactinium
• protoanthropology
• protoarchaeology
• protoarcheology
• protoavis
• protoceratops
• protocol
• protoctist
• protoctist family
• protoctist genus
• protoctist order
• Protoctista
• protogeometric
• protoheme
• protohemin
• protohippus
• protohistory
• protology