1 [noncount] : the belief that something or someone is good or acceptable : a good opinion of someone or something
children who never gained/won their parents' approval
He nodded in full approval of their decision. [=he nodded to show that he agreed with their decision]
I hope that these arrangements meet with your approval. [=I hope that these arrangements are acceptable to you; I hope that you approve of these arrangements]
The governor's approval rating with the voters is going up. [=a larger number of voters say that the governor is doing a good job]
2 : permission to do something : acceptance of an idea, action, plan, etc.
Do I have your approval to make the changes?
The change is subject to the committee's approval. [=the change must be approved by the committee]
The rally will be on May 19, provided the city gives its approval.
The company is seeking approval of the drug [=is seeking official permission to sell the drug] as a treatment for cancer.
The government has so far withheld approval of the drug.
We were required to get approvals at each stage of the project.