What it means
直ちに means “immediately” or “without delay.” It emphasizes that an action must begin at once, often in urgent instructions, official announcements, warnings, and formal writing. Compared with すぐに, it sounds more formal, forceful, and objective.
Usage note
直ちに is primarily an adverb and does not itself have a plain or polite form. The surrounding verb supplies the register. It can also mean “directly” in formal contexts, but the “immediately” meaning is especially common in instructions and official notices.
How to use it
直ちにVerb (て-form)ください
直ちに避難してください。
Evacuate immediately.
直ちにVerb (imperative form)
直ちに避難しろ。
Evacuate immediately.