Related Clues:

• Like a tuned piano string
• Like a high wire
• Like a newly-installed fan belt
• Far from slack
• With little slack
• Like a drumhead
• Having no play, say
• Sans slack
• Stretched just short of the breaking point
• Stretched tightly
• Emotionally strained
• Sans any slack
• Tensed
• Strung tightly
• Stretched very tight