noth‧er , 'nother /ˈnʌðə $ -ər/ determiner informal
a whole nother ... used humorously when emphasizing that something is completely different from what you have been talking about. It is a changed form of ‘another whole’:
Texas is a whole nother country.
That’s a whole 'nother ball game.

[TahlilGaran] Dictionary of Contemporary English ▲