THESAURUS
Origin
A, alpha, ancestry, babyhood, base, basis, beginning, beginnings, birth, birthplace, blast-off, blood, childhood, commencement, comparative linguistics, conception, cradle, creation, cutting edge, dawn, dawning, derivation, descent, edge, eponymy, establishment, etymology, extraction, flying start, folk etymology, foundation, fount, fountain, fresh start, freshman year, genealogy, genesis, grass roots, head, heritage, historical linguistics, inauguration, inception, inchoation, incipience, incipiency, incunabula, infancy, institution, jump-off, kick-off, launch, launching, leading edge, lineage, maternity, nascence, nascency, nativity, new departure, oncoming, onset, opening, original, origination, origins, outbreak, outset, parentage, parturition, paternity, pedigree, pregnancy, provenance, provenience, radical, radix, rise, root, running start, semantic history, send-off, setting in motion, setting-up, source, square one, start, start-off, starting point, stem, stock, take-off, taproot, well, wellspring, whence, word history, youth
ROGET THESAURUS
Origin
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.