One-word substitution (idiom/phrase): In a state of tension, anxiety, or suspense Select the single best expression that matches the description.

Given data

• Sought meaning: feeling very anxious/tense, waiting for an outcome.

Reasoning through options On tenterhooks — idiom meaning in a state of painful suspense/anxiety. Correct. Off balance — unsteady or surprised; not specifically suspense. Depressed — unhappy/low mood; different nuance. Diffused — spread out; unrelated.