interjection
A direct loan from English, used as an interjection to wish someone success or good fortune. Common in casual contexts, often with a friendly or encouraging tone.
明日の試験、グッドラック!
Good luck on tomorrow's exam!
新しい仕事、グッドラックだね。
Good luck with your new job.
Borrowed from English 'good luck'. The interpunct variant reflects the original two-word phrase.