The spelling of "most zillion" may seem confusing, but it can be explained using IPA phonetic transcription. The "most" part is pronounced as /moʊst/ which is the same as the word "most." The "zillion" part is pronounced as /ˈzɪljən/ which includes the consonants "z," "l," and "n." Despite being a non-standard word, "zillion" is sometimes used to mean an extremely large, but indefinite number. So, the word "most zillion" could be interpreted to mean the largest, but unknown quantity.
The phrase "most zillion" is not a standard term found in the dictionary, as it is a combination of the superlative word "most" and the exaggerated and informal word "zillion." However, "zillion" itself is not included in dictionaries either, as it is considered a nonstandard, informal term.
Despite lacking a dictionary definition, "most zillion" can be understood to convey an extremely large or countless number or quantity. Utilizing "most" as a superlative intensifier with "zillion" amplifies the notion of an immense or immeasurable amount. It is an exaggeration employed to emphasize the sheer quantity or extent of something, often in a hyperbolic or humorous manner.
The melding of "most" and "zillion" suggests the notion of surpassing an immense or incalculable quantity, even beyond what merely using the term "zillion" would imply on its own. This phrase conveys a notion of exaggeration beyond comprehension or perception, emphasizing an extraordinarily high amount without providing an exact measurement or value.
While "most zillion" isn't a standard term or phrase in dictionaries, its meaning can be derived through the association of "most" as a superlative intensifier and "zillion" as an informal way to describe a large, uncountable number.