Old Form
The elders typically use these turns of phrase, which have existed since long before the modern nights.  One is advised to use these words carefully - in some company, their use may be seen as humorously anachronistic, while in the company of anarchs, for example, they may be miscontrued as the elders' propaganda.

Amaranth - The act of consuming another Kindred's blood. (q.v. Diablerie)
Ancilla - A "proven" vampire, between the elders and the neonates.
Antediluvian - A member of the dreaded Third Generation, one of the eldest Kindred in existance.
Archon - A vampire in the retinue of a justicar.  Archons are generally nomadic in nature, frequently pursuing Kindred who have fled to avoid persecution at the hands of the Camarilla.
Autarkis - A Kindred who remains outside the larger vampire society of a given city and often refuses to acknowledge the claim of prince.
Blood Oath - The blood bond.
Cainite - A vampire; a member of the race of Caine.
Canaille - The bovine masses of humanity, especially the uncultured and unsavory.  The Canaille are viewed primarily as a source of sustenence.
Cauchemar - A vampire who feeds exclusively on sleeping victims.
Consanguineous - Literally, "of the same blood," especially with reference to lineage.
Cunctator - A vampire who avoids killing when delivering the Kiss; one who takes so little blood as to avoid bringing about her prey's death.
Domitor - A ghoul's master; one who feeds her blood and issues her commands.
Footpad - One who feeds from derelicts and other chaff of society.  Footpads are frequently debased and may not maintain permanent haven.
Gentry - A Kindred who preys at nightclubs, bars and other establishments of the "red-light district," where mortals engage in reverie.
Golconda - A fabled state of vampiric transcendence; the true mastery of the Beast and balance of opposing urges and principles.  Rumored to be similar to mortal Nirvana, Golconda is greatly touted but rarely achieved.
Humanites - The extent to which a Kindred still mantains her humanity.
Kine - A term for mortals, largely contemptuous.  the phrase 'Kindred and kine' refers to the world at large; everything.
Leech - A human who drinks vampire blood, yet acknowledges no master.
Lextalionis - The code of the Kindred and the system for punishing transgression.  It suggests Hammurabian or Biblical justice - an eye for an eye, and punishment in keeping with the grievance.
Lineage - A vampire's bloodline; the Kindred's sire, sire's sire, etc.
Methuselah - A vampire who has existed for a millennium or more; an elder who no longer exists among the greater whole of Kindred Society.  Methuselahs are rumored to hail from the Fourth and Fifth Generations.
Neonate - A young Kindred, recently Embraced.
Osiris - A vampire who builds a mortal cult around himself, in the interests of gaining sustenance.  As the millennium apprroaches and passes, Osiris cults become increasingly common.
Papillon - The red-light district; the area of town punctuated by drinking establishments, brothels, gambling houses and other locales of ill repute.  the prime hunting grounds of a city, where the disappearance of mortals goes hand in hand with the area's general seediness.
Progeny - All of a given vampire's childer, collectively.  Less formal, and less flattering, is Get.
Praxis - The right of princes to govern; the prince's claim to domain.  This term also refers to the prince's matters of policy and individual edicts and motions.
Primogen - The leaders in a given city; its ruling body of elders, typically composed of one member from each clan present in a city.
Regeant - A Kindred who holds a blood bond over another.
Retainer - A human who serves a vampiric master.  This term is almost archaic, referring to a time when vampires kept vast entourages of mortal servants as part of their estates.
Siren - A vampire who seduces mortals in order to drink from them, and then only takes a small quantity of blood, so as to avoid killing them.
Suspire - The rumored epiphany experienced just prior to the attainment of Golconda.
Third Mortal - Caine, who was cast out and became the First Vampire.
Thrall - A vampire under the effects of a blood bond, having drunk another Kindred's blood thrice.
Vitae - Blood
Whelp - A derogatory term for a young Kindred, originally used with exclusive reference to one's own progeny.
Wight - Human; man; a mortal.
Witch-Hunter - A mortal who searches out and destroys vampires.
Whig - A contemptuous term for a vampire who possesses an interest in mortal trends and fashions.