とっさ咄嗟tossani
1.

In a manner that indicates an immediate and instinctive response to a situation, often without prior thought or delay.

2.

Acting or reacting quickly in a critical moment, as if instinctively responding to an unforeseen circumstance.

3.

Performing an action instantaneously, often as a result of urgency or necessity, suggesting a high level of alertness.