under-the-table
1. [ adjective ] designed and carried out secretly or confidentially
Synonyms: sub-rosa behind-the-scenes
Examples:

"a sub-rosa report" "has their under-the-table backing"

Related terms: covert
2. [ adjective ] designed and carried out secretly or confidentially
Synonyms: sub-rosa
Examples:

"a sub-rosa report" "has their under-the-table backing"

Related terms: covert
Similar spelling:   under-the-counter
  under_the_weather