Straightaway means at once, without any delay. Go straightaway, tell him straightaway, do it straightaway.
It is British and slightly informal, and it is stronger than soon and gentler than immediately. Written as two words in American English, a straight away is also the straight section of a racetrack. Note straight, which here means direct, and away, which adds the urgency.
1adverbstraightawayAt once, without any delay.
“The doctor saw how ill she was and sent her to hospital straightaway.”
straightaway is a marker of immediacy.