互信
hù xìn · HSK 7
mutual trust
🤝 互 = mutual/each-other + 信 = trust/believe → trust that runs both ways
信 — person 亻 + speech 言
信 combines 亻(person) with 言(speech), depicting a person standing by their words. The original sense is 'truthfulness' or 'sincerity'—what a person says can be trusted. From this it extended to 'believe,' 'trust,' and later 'message' or 'letter,' since a letter carries one's word.