thih-sim鐵心

to be unshakable in one's determination

to be unshakable in one's determination; iron core

English Wiktionary, “鐵心” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E9%90%B5%E5%BF%83 · confidence: Medium (Wiktionary, Hokkien)