D defs.my
Entry 1 sense Webster, 1913

Hidden

/hĭdʹn/ · Hid·den · IPA /ˈhɪd(ə)n/
01 p. p. & a. from Hide. Concealed; put out of view; secret; not known; mysterious.
  1. 1.
    from Hide. Concealed; put out of view; secret; not known; mysterious. See: Hide
    “Bring to light the hidden things of darkness.” — 1 Cor. iv. 5.
    “My heart, which by a secret harmony Still moves with thine, joined in connection sweet.” Milton.
    “By what best way, Whether of open war, or covert guile, We now debate.” Milton.
Phrases & compounds
Hidden fifths — consecutive fifths or octaves, not sounded, but suggested or implied in the parallel motion of two parts towards a fifth or an octave.
Syn. Hidden, Secret, Covert.
Hidden may denote either known to on one; as, a hidden disease; or intentionally concealed; as, a hidden purpose of revenge. Secret denotes that the thing is known only to the party or parties concerned; as, a secret conspiracy. Covert literally denotes what is not open or avowed; as, a covert plan; but is often applied to what we mean shall be understood, without openly expressing it; as, a covert allusion. Secret is opposed to known, and hidden to revealed.