RDF

1. Radio direction-finding (or -finder)
2. Refuse-derived fuel

• periscians
• periscope
• periscopes
• periscopic
• periselenia
• periselenium
• periseleniums
• perish
• perishabilities
• premièring
• premolar
• premolars
• premonish
• premonished
• premonishes
• premonishing
• premonishment
• premonishments
• premonition
• premonitions
• premonitive
• premonitor
• premonitorily
• premonitors
• premonitory