Related Clues:

• Suspense-filled
• Frazzled
• With 50-Across, South American shocker
• Feeling nervous
• In need of a backrub
• Grammarian's subject
• Nerve-straining
• Past or present
• Full of angst
• The past, for example
• Like some cattle fences
• Not calm
• Future, for one
• Strained by time in grammar
• Rigid, or grammatical time