gnostic(n = noun.person) - an advocate of Gnosticism;
is a kind of advocate, advocator, exponent, proponent
Derived form adjective gnostic₁

1.  gnostic(a = adj.pert) - of or relating to Gnosticism; "Gnostic writings"
Derived forms noun gnosis₁, noun gnostic₁

2.  gnostic(a = adj.all) - possessing intellectual or esoteric knowledge of spiritual things;
Antonym: agnostic
Derived form noun gnosis₁

1.  Knowing; wise; shrewd. [1913 Webster]
"I said you were a gnostic fellow." [1913 Webster]

2.  Of or pertaining to Gnosticism or its adherents; as, the Gnostic heresy. [1913 Webster]

   One of the so-called philosophers in the first ages of Christianity, who claimed a true philosophical interpretation of the Christian religion. Their system combined Oriental theology and Greek philosophy with the doctrines of Christianity. They held that all natures, intelligible, intellectual, and material, are derived from the Deity by successive emanations, which they called Eons. [1913 Webster]

gnostic, adj. & n.
--adj.
1 relating to knowledge, esp. esoteric mystical knowledge.
2 (Gnostic) concerning the Gnostics; occult; mystic.
--n. (Gnostic) (usu. in pl.) a Christian heretic of the 1st-3rd c. claiming gnosis.

Derivative:
Gnosticism n. gnosticize v.tr. & intr.

Etymology:
eccl.L gnosticus f. Gk gnostikos (as GNOSIS)

N  heterodoxy, error, false doctrine, heresy, schism, schismaticism, schismaticalness, recusancy, backsliding, apostasy, atheism, bigotry, fanaticism, iconoclasm, hyperorthodoxy, precisianism, bibliolatry, sabbatarianism, puritanism, anthropomorphism, idolatry, superstition, dissent, sectarism, sectarianism, noncomformity, secularism, syncretism, protestantism, Arianism, Adventism, Jansenism, Stundism, Erastianism, Calvinism, quakerism, methodism, anabaptism, Puseyism, tractarianism, ritualism, Origenism, Sabellianism, Socinianism, Deism, Theism, materialism, positivism, latitudinarianism High Church, Low Church, Broad Church, Free Church, ultramontanism, papism, papistry, monkery, papacy, Anglicanism, Catholicism, Romanism, popery, Scarlet Lady, Church of Rome, Greek Church, paganism, heathenism, ethicism, mythology, polytheism, ditheism, tritheism, dualism, heathendom, Judaism, Gentilism, Islamism, Islam, Mohammedanism, Babism, Sufiism, Neoplatonism, Turcism, Brahminism, Hinduism, Buddhism, Sabianism, Gnosticism, Hylotheism, Mormonism, Christian Science, heretic, apostate, antichrist, pagan, heathen, painim, paynim, giaour, gentile, pantheist, polytheist, idolator, schismatic, sectary, sectarian, sectarist, seceder, separatist, recusant, dissenter, nonconformist, nonjuror, bigot, fanatic, abdal, iconoclast, latitudinarian, Deist, Theist, Unitarian, positivist, materialist, Homoiousian, Homoousian, limitarian, theosophist, ubiquitarian, skeptic, Protestant, Huguenot, orthodox dissenter, Congregationalist, Independent, Episcopalian, Presbyterian, Lutheran, Calvinist, Methodist, Wesleyan, Ana, Baptist, Mormon, Latter-day Saint, Irvingite, Sandemanian, Glassite, Erastian, Sublapsarian, Supralapsarian, Gentoo, Antinomian, Swedenborgian, Adventist, Bible Christian, Bryanite, Brownian, Christian Scientist, Dunker, Ebionite, Eusebian, Faith Curer, Curist, Familist, Jovinianist, Libadist, Quaker, Restitutionist, Shaker, Stundist, Tunker, ultramontane, Anglican, Oxford School, tractarian, Puseyite, ritualist, Puritan, Catholic, Roman, Catholic, Romanist, papist, Jew, Hebrew, Rabbinist, Rabbist, Sadducee, Babist, Motazilite, Mohammedan, Mussulman, Moslem, Shiah, Sunni, Wahabi, Osmanli, Brahmin, Brahman, Parsee, Sufi, Buddhist, Magi, Gymnosophist, fire worshiper, Sabian, Gnostic, Rosicrucian, heterodox, heretical, unorthodox, unscriptural, uncanonical, antiscriptural, apocryphal, unchristian, antichristian, schismatic, recusant, iconoclastic, sectarian, dissenting, dissident, secular, (lay), pagan, heathen, heathenish, ethnic, ethnical, gentile, paynim, pantheistic, polytheistic, Judaical, Mohammedan, Brahminical, Buddhist, Romish, Protestant, bigoted superstitious, fanatical, idolatrous, visionary, slave to no sect, superstitione tollenda religio non tollitur.