至急

1. Origins, structure, and basic meaning

• Structure: 至急 is read as しきゅう and is an adverbial noun adding strong urgency to the action that follows.
• Basic usage: It is used to request an immediate leak check or urgent shipment of missing parts.

2. Common pitfalls and similar expressions

• Position before the action
  • It appears directly before the required action in 至急確認する and 至急送る.
• Urgency rather than a clock time
  • It does not specify an exact time; it says the task should be prioritized without delay.