1. The principal operculum of fishes

Derived forms: operculars

• perestroika
• perfect
• perfect game
• perfect gas
• perfect number
• hidden tax
• hiddenite
• hiddenness
• hide
• hide and go seek
• hide-and-seek
• hideaway
• hidebound
• Hideki Yukawa
• hideous
• hideously
• hideousness
• hideout
• hider
• hidey-hole
• Hideyo Noguchi
• hiding
• hiding place
• hidrosis
• hidrotic