Dramatic monologue--Please copy down the definition below and any lines in blue

dramatic monolgue- a speech in  poetic form, in which a single character, addressing a silent auditor (listener) at a critical moment, reveals himself or herself and the dramatic situation.

Macbeth: (Act III, sc. i)
To be thus is nothing;
But to be safely thus.--Our fears in Banquo (what does he mean by this?)
Stick deep; and in his royalty of nature
Reigns that which would be fear'd: 'tis much he dares;
And, to that dauntless temper of his mind,
He hath a wisdom that doth guide his valour (why does he fear Banquo?)
To act in safety. There is none but he
Whose being I do fear: and, under him,
My Genius is rebuked; as, it is said, 
Mark Antony's was by Caesar. He chid the sisters
When first they put the name of king upon me,
And bade them speak to him: then prophet-like
They hail'd him father to a line of kings:
Upon my head they placed a fruitless crown, (what is the "fruitless crown" he describes?)
And put a barren sceptre in my gripe,
Thence to be wrench'd with an unlineal hand,
No son of mine succeeding. If 't be so,
For Banquo's issue have I filed my mind;
For them the gracious Duncan have I murder'd; (who are "them"?)
Put rancours in the vessel of my peace
Only for them; and mine eternal jewel
Given to the common enemy of man,
To make them kings, the seed of Banquo kings!
Rather than so, come fate into the list. 
And champion me to the utterance!

Now, let's try to figure out these lines on our own:

Macbeth: (Act III, sc. ii)

We have scorched the snake, not killed it. (What is the "snake"-what does it mean that it is scorched but not killed?)

She’ll close and be herself whilst our poor malice

Remains in danger of her former tooth.

But let the frame of things disjoint, both the worlds suffer,

Ere we will eat our meal in fear, and sleep (according to Macbeth, why is Duncan better off than he is?)

In the affliction of these terrible dreams

That shake us nightly. Better be with the dead,

Whom we, to gain our peace, have sent to peace,

Than on the torture of the mind to lie

In restless ecstasy. Duncan is in his grave.

After life’s fitful fever he sleeps well.

Treason has done his worst; nor steel nor poison,

Malice domestic, foreign levy, nothing

Can touch him further.