Crossword clue: lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed)

The most common answer is subterranean (12 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

subterranean 12 letters wn-def

lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed)

subterraneous 13 letters wn-def

lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed)