If people or their opinions are upbeat, they are cheerful and hopeful about a situation.
例句
The Defense Secretary gave an upbeat assessment of the war so far...國防部長對目前的戰事給予了樂觀的評價。Neil's colleagues say he was actually in a joking, upbeat mood...內爾的同事們說他實際上在說笑逗樂，心情不錯。
N-COUNT
弱拍；上拍
In music, the upbeat is the beat before the first beat of the bar.
英英詞典釋義
Noun
1. a contented state of being happy and healthy and prosperous;
"the town was finally on the upbeat after our recent troubles"
2. an unaccented beat (especially the last beat of a measure)