ADJ-GRADED 秘密的;鬼祟的;偷偷摸摸的 If you describe someone as sneaky, you disapprove of them because they do things secretly rather than openly. 秘密的;鬼祟的;偷偷摸摸的 [informal, disapproval]
It is a sneaky and underhand way of doing business.
这种做生意的方式偷偷摸摸,遮遮掩掩。
One kid can generally tell when another kid is sneaky.