What does this mean?

Question

There the grown serpent lies; the worm that's fled
Hath nature that in time will venom breed,
No teeth for the present.

Thanks in advance! :)

Answer 1

It is prophesied by the three witches that Banquo's descendants are to be king one day. Fleance is Banquo's son. He and his father are ambushed by assassins sent by Macbeth. His father is murdered, but Fleance escapes.
Fleance, the worm, that escaped will in time breed a venom or line of kings Macbeth was hoping to prevent.

Answer 2

Macbeth likens the dead Banquo to a deceased serpent and his son Fleance to a young snake. This metaphor is important because it implies that Macbeth still considers Fleance a threat even though Banquo is dead.

Answer 3

my interpretation is that right now the serpent is as harmless as a worm, but following its nature, will be venemous.

its like a kind persons inner bitterness coming out later..