If you describe something as mediocre, you mean that it is of average quality but you think it should be better.
例句
His school record was mediocre.他在學校成績平平。...mediocre music.不盡如人意的音樂
英漢詞典釋義
adj.
平庸的；普通的；平常的
mediocre work平庸的作品
英英詞典釋義
Adjective
1. moderate to inferior in quality;
"they improved the quality from mediocre to above average""he would make a poor spy"
2. of no exceptional quality or ability;
"a novel of average merit""only a fair performance of the sonata""in fair health""the caliber of the students has gone from mediocre to above average""the performance was middling at best"
3. poor to middling in quality;
"there have been good and mediocre and bad artists"