not openly; inwardly; "they were secretly delighted at his embarrassment"; "hoped secretly she would change her mind"
in secrecy; not openly; "met secretly to discuss the invasion plans"; "the children secretly went to the movies when they were supposed to be at the library"; "they arranged to meet in secret"
based on custom rather than documentation; "an unwritten law"; "rites...so ancient that they well might have had their unwritten origins in Aurignacian times"- J.L.T.C.Spence
articulate (a consonant) with the tongue curled back against the palate; "Indian accents can be characterized by the fact that speakers retroflex their consonants"