au grand sérieux /ō grã sā-ryøˈ/ (French; now très au sérieux /tre-zō/) in all seriousness.

• planchettes
• planching
• Planck's constant
• Planck's law
• 'plane
• plane
• plane chart
• plane charts
• planed
• plane of flotation
• plane-polarised
• plane-polarized
• planer
• planers
• planes
• plane sailing
• planet
• plane table
• plane tabled
• plane tables
• plane tabling
• planetaria
• planetarium
• planetariums
• planetary