Related Clues:

• Vigour, power
• Get-up-and-go, vitality
• Vigour, vitality
• Ceremony for many
• Vigour, vim, vitality
• Healthy capacity for vigorous activity
• Exertion of force
• Christian ritual
• It's measured in joules
• It's measured in joules or ergs
• 'Vigour, vitality (6)'
• Strength, vitality
• Can you force this to become greeny?
• Forceful enough to make Y green
• The force needed to make Y green?