In Act IV, scene i with the witches, what do "blaspheming" and "chaudron" mean?

I think you are referring to the passage below:

THIRD WITCH.
Scale of dragon, tooth of wolf,
Witch's mummy, maw and gulf
Of the ravin'd salt-sea shark,
Root of hemlock digg'd i' the dark,
Liver of blaspheming Jew,
Gall of goat, and slips of yew
Sliver'd in the moon's eclipse,
Nose of Turk, and Tartar's lips,
Finger of birth-strangl'd babe
Ditch-deliver'd by a drab,--
Make the gruel thick and slab:
Add thereto a tiger's chaudron,
For the ingredients of our caldron.

Because Shakespeare's language is so archaic, it is sometimes difficult to understand. Fortunately, Enotes has side-by-side etexts for many of Shakespeare's plays. They show both the original and a modern translation of the play.

Below is the paraphrase for the lines you were unsure of:

THIRD WITCH.
Scale of dragon, tooth of wolf,
Witch's mummy, a gulf-like stomach,
Of the rough sea salt glisten,
Root of poison hemlock dug up in the dark,
Liver of Christians not baptized,
Gall bladder of goat, and slips of pine trees
Cut off the tree when the moon eclipsed,
Nose of Turk, and Tartar's lips,
Finger of a baby born dead
Delivered in a ditch by a prostitute,
Make the gruel thick and gooey.
Also add a tiger's guts,
For the ingredients of our caldron.

You can see the rest of the text at the link below: