tonus /tōˈnəs/ (medicine)

1. The normal elasticity of healthy muscle at rest, tonicity
2. Atonic spasm

• 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
• first-class mail
• first-class post
• first cousin
• first cousin once removed
• first-day
• first-day cover