底子 (dǐ zi): Foundation / Basis (Noun) — Meaning & Stroke Order

The bottom of this cup is very thick.

He has a good foundation in English, so he is making rapid progress.

Without a solid theoretical foundation, any innovation is merely a castle in the air.

His foundation in mathematics is not weak; he has just been lacking practice recently.

Although this company is facing difficulties now, it has a solid foundation and should be able to overcome the challenges.

Despite severe market fluctuations, the company continues to develop steadily thanks to its substantial capital foundation and prudent strategy.