The spelling of the word "most at" can be explained with IPA phonetic transcription as /moʊst æt/. The first syllable "mo" is pronounced with a long "o" sound, followed by the "-st" ending which represents the superlative form of the adjective "most." The second syllable "at" is pronounced with a short "a" sound and is commonly used as a preposition to indicate location or direction. Together, the word "most at" suggests a state or situation of being at the highest or greatest extent.
The phrase "most at" does not have a specific etymology, as it is not a single word or a common phrase. It seems to be a combination of the word "most" - which can be used as an adverb or pronoun indicating the greatest amount, degree, or extent - with the preposition "at" - which typically expresses location or point in time.