Blab verb – Divulge confidential information or secrets. Give away is a synonym for blab in show topic. In some cases you can use "Give away" instead a verb "Blab", when it comes to topics like tell, gossip, blurt out.
Give away verb – To make known (something abstract) through outward signs. Blab is a synonym for give away in reveal topic. You can use "Blab" instead a verb "Give away".