1. Having a form maintained by a rigid internal structure as well as by internal gas pressure 
2. Not fully rigid

See also: inflexible, rigid

• Arenaria stricta
• Arenaria-Melanocephala
• Arenaviridae
• arenavirus
• Arendt
• Arenga
• Arenga pinnata
• arenicolous
• areola
• areolar
• areolar tissue
• areolate
• Areopagite
• Areopagus
• Arequipa
• arere
• Ares
• areteria cervicalis
• arethusa
• Arethusa bulbosa
• argal
• argali
• argasid
• Argasidae
• argemone