Idiom
give a thumbs up something(give a) thumbs up to (someone/something)
to show approval of or support for someone or something.Voters gave a thumbs up to building swimming pool for the town.
Usage notes: often used in the form give the thumbs up (to something):
We have been given the thumbs up and will begin work next week.
Opposite of: (give a) thumbs down to (someone/something)