Available Definitions:
1) a. - Fixed or determined by nature; pertaining to the constitution of a thing; belonging to native character; according to nature; essential; characteristic; not artifical, foreign, assumed, put on, or acquired; as, the natural growth of animals or plants; the natural motion of a gravitating body; natural strength or disposition; the natural heat of the body; natural color.
2) a. - Conformed to the order, laws, or actual facts, of nature; consonant to the methods of nature; according to the stated course of things, or in accordance with the laws which govern events, feelings, etc.; not exceptional or violent; legitimate; normal; regular; as, the natural consequence of crime; a natural death.
3) a. - Having to do with existing system to things; dealing with, or derived from, the creation, or the world of matter and mind, as known by man; within the scope of human reason or experience; not supernatural; as, a natural law; natural science; history, theology.
4) a. - Conformed to truth or reality
5) a. - Springing from true sentiment; not artifical or exaggerated; -- said of action, delivery, etc.; as, a natural gesture, tone, etc.
6) a. - Resembling the object imitated; true to nature; according to the life; -- said of anything copied or imitated; as, a portrait is natural.
7) a. - Having the character or sentiments properly belonging to one's position; not unnatural in feelings.
8) a. - Connected by the ties of consanguinity.
9) a. - Begotten without the sanction of law; born out of wedlock; illegitimate; bastard; as, a natural child.
10) a. - Of or pertaining to the lower or animal nature, as contrasted with the higher or moral powers, or that which is spiritual; being in a state of nature; unregenerate.
11) a. - Belonging to, to be taken in, or referred to, some system, in which the base is 1; -- said or certain functions or numbers; as, natural numbers, those commencing at 1; natural sines, cosines, etc., those taken in arcs whose radii are 1.
12) a. - Produced by natural organs, as those of the human throat, in distinction from instrumental music.
13) a. - Of or pertaining to a key which has neither a flat nor a sharp for its signature, as the key of C major.
14) a. - Applied to an air or modulation of harmony which moves by easy and smooth transitions, digressing but little from the original key.
15) n. - A native; an aboriginal.
16) n. - Natural gifts, impulses, etc.
17) n. - One born without the usual powers of reason or understanding; an idiot.
18) n. - A character [/] used to contradict, or to remove the effect of, a sharp or flat which has preceded it, and to restore the unaltered note.