彻底 (chè dǐ): тщательный

Before moving into our new home, we spent three days thoroughly cleaning every room, not even missing the dust in the window cracks.

The surgery was very successful; the doctor said the tumor in his body had been completely removed, and he just needs regular check-ups from now on.

In order to completely break her bad habit of staying up late, she put her phone in the living room at ten every night and went back to the bedroom to read. After two months of persistence, her daily routine finally became normal.

After an investigation, the company found that the problems with that batch of products were due to loopholes in the production process, so it decided to thoroughly check all steps.

After that fierce argument, the trust between the two of them was completely shattered; even though they later apologized to each other, they could never go back to the way things were.