the thumbs down为“名词+副词”结构，副词作后置定语修饰前面的“thumbs” 意思“向下的拇指”
give sb the thumbs down=字面意思“给某人向下拇指” 就是反对/不赞同/拒绝。
thumbs down/up ( 英文解释 used to show that sth has been accepted/rejected or that it is/is not a success 翘拇指（表示接受或成功）；拇指向下（表示拒绝或不成功））
Their proposals were given the thumbs down .他们的建议遭到拒绝。
It looks like it's thumbs up for their latest album.看样子他们的最新歌曲专辑成功了。
