also: ラジャー
Casual acknowledgment used in radio communication or playful everyday speech; equivalent to 'got it' or 'copy that'.
"Roger, understood!" he replied over the radio.
友達に「明日10時に集合ね」と言われて、「ラジャ！」と答えた。
When my friend said, "Let's meet at 10 tomorrow," I answered, "Roger!"