Give away and Open up

Give away verb - To make known (something abstract) through outward signs.

Open up and give away are semantically related In some cases you can use "Open up" instead a verb "Give away".

Open up verb - Cause to open or to become open.

Give away and open up are semantically related in confess topic. Sometimes you can use "Give away" instead a verb "Open up", if it concerns topics such as reveal.