1.nounAn expression granting permission; an indication of agreement with a proposal; an acknowledgement that a person, thing or event meets requirements.
"I need to get an approval on this purchase order."
2.nounAn expression of favorable acceptance and encouragement; a compliment that also condones.
"Words of approval never seem to come from him."
3.nounSomething mailed by a seller to a collector to match their stated interests; the collector can approve of or return the item.