Synonyms for Natural:

adj.

animal (adjective)
untamed.
artless (adjective)
naive, outgoing, frank, unadorned, direct, honest, overt, un-artificial, unsophisticated, unrestrained, plain, candid, ingenuous, unaffected, uncalculating, undisguised, genuine, sincere, straightforward, downright, undeceiving, open, Unbeguiling, blunt, callow, trusting, undeceitful, artless, Unartful, broad, undeceptive, Plain-spoken, unpretentious.
good-humored (adjective)
easy.
habitual (adjective)
habitual.
lifelike (adjective)
faithful, realistic, vivid, lifelike, exact.
open, unaffected (adjective)
homey, ingenuous, impulsive, credulous, unsophisticated, artless, unworldly, childlike, direct, unstudied, genuine, easy, naive, laid-back, trusting, unpolished, real, frank, unpretentious, candid, unfeigned, plain, straightforward, rustic, simple, folksy, sincere, innocent, forthright.
plainspoken (adjective)
Plain-spoken.
simple (adjective)
artless.
untamed (adjective)
wild.

n.

past master, old hand, master, unsuspecting, queen, maestro, unfeigned, unpolished, best, prodigy, exponent, homey, simple, unstudied, artist, innocent, childlike, credulous, forthright, rustic, unpretentious, superman, impulsive. addictive, flawed, adaptive, Clingy, actual, flexible, constitutionally, classy, badass, babyish. upstanding, fine, unadulterated, culture, organic, irreproachable, principled, good. wild, core, untamed, basic, uncultivated, rudimentary, undomesticated, rough. daddy, father, birth father, empty nester, built-in, constitutional, start, be, birth mother, fatherhood, dad, indigenous, custodial parent, birth parent, deadbeat dad, connatural. natural resources, element, ecosystem, guileless, resource, ecology, the environment, raw materials, unworldly, the biosphere, nature. homespun, unadorned, homely. truthful, true-life, naturalistic. natural (noun)
biological, born, innate, self-generated, normal, intelligent, spontaneous, lifelike, physical, raw, undyed, elemental, instinctive, earthy, unaffected, unbleached, fresh, unprocessed, rude, uncolored, cancel.

Other synonyms:

just, accepted, easy, connatural, regular, baseborn, fair-minded, true-life, Familiar, naturalistic, uncultivated, laid-back, unbiased, undomesticated, untamed. relaxed, fair, homely, truthful. core, unlawful. spurious, unworldly. basic, unpolished. simple. true. rough. baseborn
misbegotten.
commonplace
common.
distinctive
characteristic.
ordinary
usual.
routine
matter of course.
unaffected
childlike.
without formality
informal.

Usage examples for natural

  1. " I loved this little girl, as it was natural I should, more than I loved the other, whose mother was a servant. – Bad Hugh by Mary Jane Holmes
  2. True; all that would be most natural – Dawn by Mrs. Harriet A. Adams
  3. Well, it's natural he should. – The Judgment House by Gilbert Parker