Change EDIT to UNDO

Question

On your computer right now, you can probably click on the "Edit" menu; and one of the first options will be "Undo". These are closely associated words. But how close are they in a word ladder?

Challenge: Change EDIT to UNDO by changing one letter at a time. Each intermediate word must be a valid word in (modern) English.

The accepted answer will be:

1. The shortest chain of words that uses only uncapitalized words (i.e., no proper nouns) in Merriam-Webster Dictionary (and their pluralizations, tenses, etc.)

2. If no such answer is found, the shortest chain of words including proper nouns from the Merriam-Webster Dictionary.

3. If no such answer is found, the shortest chain of words using any other modern English dictionary, including proper nouns.

Acronyms are not allowed. I know of a solution satisfying criterion #1, which uses one relatively obscure word.

EDIT: somehow I forgot that there were words other than nouns. My intent was only to prohibit proper nouns in Criterion #1, not to prohibit any words other than nouns.

Answer 1

Edit: These are all in Merriam-Webster and the steps are all nouns (one an abbreviation).

EDIT EPIT SPIT SNIT UNIT UNIO UNDO
6 steps.

These are all in Merriam-Webster but they are not all nouns (proper or improper).

EDIT EMIT SMIT SNIT UNIT UNIO UNDO
6 steps.