How do you say "in secret" in Hokkien?

2 ways to say “in secret” in Philippine Hokkien.

• àm-tsǐnn暗靜 in secret; in private; surreptitiously; behind someone's back; privately; on the sly Hear it said
• kha-tshng-ǎu尻川後 in secret; in private; surreptitiously; behind someone's back; privately; on the sly Hear it said

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