Sit tight and Stick around

Sit tight verb - Maintain the same position; wait it out.

Stick around and sit tight are semantically related in wait topic. In some cases you can use "Stick around" instead a verb phrase "Sit tight".

Stick around verb - To continue to be in a place for a significant amount of time.

Sit tight and stick around are semantically related in stay topic. You can use "Sit tight" instead a verb "Stick around", if it concerns topics such as wait, pause.