pygostyle /pīˈgō-stīl/ (zoology)

The bone of a bird's tail

• firmware
• firmwares
• firn
• firns
• firrier
• firriest
• firring
• firry
• firs
• first
• first aid
• first-aider
• first-aiders
• first and last
• first-attack
• first-begotten
• first blood
• first blush
• First Book of Discipline
• first-born
• first cab off the rank
• first catch your hare
• first cause
• first chop
• first-class