Descriptive:
* The tranquil lake reflected the blue sky like a mirror.
* After a stressful day, I find it calming to walk in the tranquil forest.
* The tranquil atmosphere of the spa helped me to relax and unwind.
Figurative:
* Her mind was a tranquil oasis amidst the chaos of the city.
* The music created a tranquil mood that transported me to another place.
Contrasting:
* The tranquil countryside stood in stark contrast to the bustling city.
* Despite the tranquil exterior, she was battling inner turmoil.
Action:
* The doctor prescribed medication to help him tranquilize his racing thoughts.
* We sought to tranquilize the situation by mediating between the two parties.