Hey Santana, the scripture is a pretty good dictionary. I looked throughout the bible at every occasion of the word serpent that appears in Genesis 3. Let's see how the bible generally defines "serpent".
Genesis 49:17 Dan shall be a serpent by the way, an [b]adder in the path[/b], that biteth the horse heels, so that his rider shall fall backward.
Serpents hang out by the way, they bite, and they are comparable to adders. [url=http://www.wartsoc.co.uk/images/adder_1.jpg]picture of an adder[/url]
Exodus 4:2 And the LORD said unto him, What is that in thine hand? And he said, A rod. 3And he said, Cast it on the ground. And he cast it on the ground, and it became a serpent; and Moses fled from before it. 4And the LORD said unto Moses, Put forth thine hand, and take it by the [b]tail[/b]. And he put forth his hand, and caught it, and it became a rod in his hand.
They have tails! And they look like snakes to Moses (if it looked too unusual he might not have known to flee it).
Numbers 21:6 And the LORD sent fiery serpents among the people, and they bit the people; and much people of Israel died.
Like poisonous snakes again.
Job 26:13 By his spirit he hath garnished the heavens; his hand hath formed the crooked [b]serpent[/b].
They are sometimes crooked, and in more than one way. ;-)
Psalm 58:4 Their poison is like the poison of a serpent: they are like the deaf [b]adder[/b] that stoppeth her ear;
Again, like adders.
Psalm 140:3 They have [b]sharpened their tongues like a serpent[/b]; adders’ poison is under their lips.
Sharp tongues.
Proverbs 23:32 At the last it biteth like a serpent, and stingeth like an adder.
Sharp teeth.
Proverbs 30: 19The way of an eagle in the air; the way of a [b]serpent upon a rock[/b]; the way of a ship in the midst of the sea; and the way of a man with a maid.
They loiter on rocks.
Micah 7:17 They shall lick the dust like a serpent,
Low-lying.
A snake with legs, lying on a rock.
You may want to skim through this artice...
[url=http://www.answersingenesis.org/creation/v13/i4/serpent.asp]About the serpent[/url]