(ただ)ちに

ただちに
adverb
immediately, at once, right away
1. immediately, at once, right away
Without any delay; instantly.
We need to take action immediately.
If the fire alarm sounds, please evacuate immediately.
Upon receiving the report, the president immediately held a meeting.

(ただ)ちに is a formal adverb meaning 'immediately' or 'at once.' It's commonly used in official announcements, instructions, and formal writing.

REGISTER: Formal

SIMILAR EXPRESSIONS (from formal to casual):

(ただ)ちに emphasizes urgency and no delay. It's often seen in emergency instructions, legal documents, and formal requests.