thumbs up

Từ điển Oxford Advanced Learner 8th

thumbs ˈup/ˈdown idiom
(informal)used to show that sth has been accepted/rejected or that it is/is not a success
•Their proposals were given the thumbs down.
•It looks like it's thumbs up for their latest album. In contests in ancient Rome the public put their thumbs up if they wanted a gladiator to live, and down if they wanted him to be killed.
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