sim-pak心腹

chest and abdomen

chest and abdomen; vital organ; crucial or strategic position; close confidant; trustworthy person; trusted aide; one's true intentions

English Wiktionary, “心腹” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%BF%83%E8%85%B9 · confidence: Medium (Wiktionary, Hokkien)