THESAURUS
Source
adviser, ambition, announcer, annunciator, antecedent, aspiration, author, authority, authorship, basis, begetter, beginning, birthplace, bonanza, calling, cause, channel, commencement, communicant, communicator, conception, consideration, cornucopia, creator, dawn, dawning, derivation, determinant, documentation, enlightener, expert witness, font, fount, fountain, fountainhead, genesis, goal, gold mine, gossipmonger, grapevine, grass roots, ground, guiding light, guiding star, head, headstream, headwater, headwaters, ideal, inception, informant, information center, information medium, informer, inspiration, intention, interviewee, lode, lodestar, mainspring, matter, mine, monitor, mother, motive, mouthpiece, newsmonger, notifier, onset, opening, origin, original, origination, originator, outset, parent, paternity, press, principle, provenance, provenience, public relations officer, publisher, quarry, radical, radio, radix, reason, reporter, resource, rise, rising, riverhead, root, roots, rootstock, sake, score, source of supply, spokesman, spring, staple, start, starting, stem, stock, taproot, television, teller, tipster, tout, ulterior motive, vein, vocation, well, wellhead, wellspring, whence, witness
ROGET THESAURUS
Source
Beginning
N
beginning, commencement, opening, outset, incipience, inception, inchoation, introduction, alpha, initial, inauguration, debut, le premier pas, embarcation, rising of the curtain, maiden speech, outbreak, onset, brunt, initiative, move, first move, narrow end of the wedge, thin end of the wedge, fresh start, new departure, origin, source, rise, bud, germ, egg, rudiment, genesis, primogenesis, birth, nativity, cradle, infancy, start, inception, creation, starting point, dawn, evolution, title-page, head, heading, van, caption, fatihah, entrance, entry, inlet, orifice, mouth, chops, lips, porch, portal, portico, propylon, door, gate, gateway, postern, wicket, threshold, vestibule, propylaeum, skirts, border, first stage, first blush, first glance, first impression, first sight, rudiments, elements, outlines, grammar, alphabet, ABC, beginning, initial, initiatory, initiative, inceptive, introductory, incipient, proemial, inaugural, inchoate, inchoative, embryonic, rudimental, primogenial, primeval, primitive, primordial, aboriginal, natal, nascent, first, foremost, leading, maiden, begun, just begun, at the beginning, in the beginning first, in the first place, imprimis, first and foremost, in limine, in the bud, in embryo, in its infancy, from the beginning, from its birth, ab initio, ab ovo, ab incunabilis, ab origine, let's get going!, let's get this show on the road!, up and at 'em!, aller Anfang ist schwer, dimidium facti qui coepit habet, omnium rerum principia parva sunt.
Cause
N
cause, origin, source, principle, element, occasioner, prime mover, primum mobile, vera causa, author, mainspring, agent, leaven, groundwork, foundation, spring, fountain, well, font, fountainhead, spring head, wellhead, fons et origo, genesis, descent, remote cause, influence, pivot, hinge, turning point, lever, crux, fulcrum, key, proximate cause, causa causans, straw that breaks the camel's back, ground, reason, reason why, why and wherefore, rationale, occasion, derivation, final cause, les dessous des cartes, undercurrents, rudiment, egg, germ, embryo, bud, root, radix radical, etymon, nucleus, seed, stem, stock, stirps, trunk, tap-root, gemmule, radicle, semen, sperm, nest, cradle, nursery, womb, nidus, birthplace, hotbed, causality, causation, origination, production, caused, causal, original, primary, primitive, primordial, aboriginal, protogenal, radical, embryonic, embryotic, in embryo, in ovo, seminal, germinal, at the bottom of, connate, having a common origin, because, behind the scenes, causa latet vis est notissima, felix qui potuit rerum cognoscere causas.