àm-tsǐnn暗靜

in secret

in secret; in private; surreptitiously; behind someone's back; privately; on the sly

adverb

English Wiktionary, “暗靜” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E6%9A%97%E9%9D%9C · confidence: Medium (Wiktionary, Hokkien)