Definition: not openly made known
Usage: a secret marriage; a secret bride
Similar words: unacknowledged
Definition: not recognized or admitted
Synonyms: unavowed
Definition: not affirmed or mentioned or declared
Similar words: undeclared
Definition: not announced or openly acknowledged
Usage: fighting an undeclared war
Definition: not openly expressed
Usage: a sneaking suspicion
Similar words: concealed
Definition: hidden on any grounds for any motive
Usage: a concealed weapon; a concealed compartment in his briefcase