Pronunciation: [mˈə͡ʊst bˈɛtəɹɪŋ] (IPA) 
The spelling "most bettering" is incorrect. "Most" refers to a superlative degree, while "bettering" is a gerund form of the verb "to better." The correct form would be "most improving," which follows the grammatical rules of English. The phonetic transcription of "most improving" is /moʊst ɪmˈpruːvɪŋ/, where the stressed syllables are marked with a slash and the sounds are written in IPA symbols.
There doesn't seem to be a widely recognized or accepted definition for the term "most bettering" in the English language. The phrase "most bettering" doesn't follow typical grammatical conventions or commonly used idiomatic expressions.
"Most" is an intensifier often used to compare or emphasize the degree of something, typically accompanied by an adjective or adverb. However, "most bettering" is an unusual combination that is not typically used in everyday language or recognized as a valid phrase.
If we were to speculate on the possible meaning of "most bettering," it could potentially be interpreted as a superlative expression emphasizing the act or process of improvement or advancement to the highest possible degree. In this hypothetical context, "most bettering" would suggest the utmost effort or outcome in terms of positive change or progress.
Nonetheless, without a clear context or specific usage example, it is challenging to provide an accurate definition for "most bettering." It is essential to note that the phrase doesn't appear to have a standard meaning in the English language, and further clarification or context would be necessary for a more precise interpretation.
