周密 (zhōu mì): careful; thorough; meticulous

The security plan for this event was extremely thorough; they even rehearsed crowd control at every entrance and exit twice in advance.

To ensure the accuracy of the experimental data, she established a meticulous recording procedure that required every step to be signed and confirmed on the spot.

After a careful investigation, the police finally located the hiding place of the suspect.

He is always meticulous; before setting out, he not only checked the weather but also wrote down backup routes and emergency contacts in his notebook.