"This evening at 7 o'clock" 翻译为 "今晚七点"。
"This evening" 是 "今晚" 的意思，是指当天的傍晚或晚上。
"at 7 o'clock" 是指七点钟，"o'clock" 是指整点。
例句：
I'll see you this evening at 7 o'clock. (我今晚七点见你)
We're having a meeting this evening at 7 o'clock. (我们今晚七点开会)
I'll be home this evening at 7 o'clock. (我今晚七点回家)