Definition of prime :
1. Divisible by no number except itself or unity; as, 7 is a prime number.
2. Having no common factor; - used with to; as, 12 is prime to 25.
3. That which makes, or helps to make, anything such as it is; anything belonging to a subject, or predicable of it; distinguishing property, characteristic, or attribute; peculiar power, capacity, or virtue; distinctive trait; as, the tones of a flute differ from those of a violin in quality; the great quality of a statesman.
meridian, anthesis, good, bully, first-class, heyday, bloom, flower, tiptop, establish, vizor, prize, rush, prime quantity, uncreated, start, blossoming, capital, florescence, acme, important, boot, crest, swell, base, efflorescence, patriarchal, bloom of youth, banner, found, native, original, paramount, great, primordial, peak, boss, rosiness, salad days, visor, dandy, crown, better, flush, initial, blush, immemorial, skin rash, pinnacle, champion, indigenous, superb, tip, topflight, principal, old, top, extremum, blossom, pristine, charge, bang, flowering, key, elevation, autochthonic, apex, run aground, earliest, premier, major, roseola, eyeshade, topnotch, first-rate, ancient, pioneer, number one, terrific, cardinal, tophole, vertex, summit, ground, foremost, primitive, leading, rash, kick, bill, first, prime of life, inflorescence, chief, gush, beginning, thrill, height, primeval, anchor, maiden, quality, hot flash, brag, undercoat, outpouring, blooming, main, blue-ribbon, point, A-one, strand
excellent (part of speech: adjective)
pure (part of speech: adjective)
basic, innocent, blameless, angelic, plain, pure, aboriginal, honorable, faultless, primal, undiluted, purebred, basal, guiltless, elemental, unadulterated, spotless, uncluttered, indivisible, unsullied, undefiled, unblemished, elementary, sinless, fundamental, simon-pure, stainless, irreducible, primary, monolithic, essential, austere, clear, stark, unadorned, white, unalloyed, virtuous, chaste, bare, decent, clean, atomic, untarnished, untainted, nascent, immaculate, formative, foundational, simple
prepare (part of speech: verb)