1. characterized by, done in, or executed with secrecy or concealment, especially for purposes of subversion or deception; private or surreptitious: Their clandestine meetings went undiscovered for two years.
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hidden, underhand, confidential, illicit.
Origin: 1560-70; < Latin clandestīnus, equivalent to *clande, *clamde, variant of clam secretly (with -de adv. particle) + -stīnus, probably after intestīnus internal; see intestine
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