What is a North-America™ word?

This puzzle is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles.

If a word conforms to a special rule, I call it a North-America™ word. Here is a list of North-America™ and not North-America™ words:

And CSV version:

North-America™ Word,Not a North-America™ Word
Colonial,Explorer
Debate,Argue
Imperial,Island
Judicial,Judge
Popular,Ordinary
Superficial,Fake
Universal,Earth
Singular,Country
Vulnerable,Sick


QUESTION: What is the rule to tell whether a word is a North-America™ word or not?

North-America words are

english (american) and also spanish (mexican)

OP edit:

More specifically they are exact English-Spanish Cognates

• This looks to be correct, although the question then seriously overlooks rot13(Serapu) in all this.... – El-Guest Oct 24 '20 at 11:46
• This is correct! These words are rot13(rknpg Ratyvfu-Fcnavfu Pbtangrf). – Kyle Williamson Oct 24 '20 at 13:08
• @El-Guest I thought about that. rot13(Ubjrire, bayl nebhaq <3% bs gur cbchyngvba va AN fcrnx Serapu.) I had to cut it off somewhere. – Kyle Williamson Oct 24 '20 at 13:12
• Haha @KyleWilliamson no worries — I’m Canadian which is why I noticed right away! – El-Guest Oct 24 '20 at 14:31

Based on the data available, one of the option for the rule can be as follows:

North American word has a minimum of 3 vowels. If the NA word starts with a vowel, there should be 3 more vowels. If this condition is not satisfied, it is Not a NA word.

Words that meet the North American word rule:

Colonial - 3 vowels
Debate - 3 vowels
Imperial - 3 vowels excluding the first I
Judicial - 3 vowels
Popular - 3 vowels
Superficial - 3 vowels
Universal - 3 vowels excluding the first U
Singular - 3 vowels
Vulnerable - 3 vowels

Words that DO NOT meet the North American word rule

Explorer - has only 2 vowels excluding the first E
Argue - has only 2 vowels excluding the first A
Island - has only 1 vowel excluding the first I
Judge - has only 2 vowels
Ordinary - has only 2 vowels excluding the first O
Fake - has only 2 vowels
Earth - has only 1 vowel excluding the first E
Country - has only 2 vowels
Sick - has only 1 vowel

• I think this rule is too complex. It also does not explain the title – melfnt Oct 24 '20 at 8:07
• This is incorrect. I added the "Language" tag, which I should've had at the beginning. I'm fairly new to Puzzling and didn't realize that tag existed. – Kyle Williamson Oct 24 '20 at 10:50
• But by adding that tag it should work as a clue. – Kyle Williamson Oct 24 '20 at 10:51