The spelling of "am smooth" is influenced by the phonetic transcription of the word. In IPA, the /æ/ sound in "am" is followed by the voiced dental fricative /ð/ sound in "smooth", creating the unique combination of the two sounds. This sound can be spelled in different ways depending on the context and language, but in English, it is commonly spelled as "th" or "thh" as in "this" or "clothes". Therefore, the spelling of "am smooth" using the English alphabets is phonetically appropriate.
The term "am smooth" does not have an established etymology. It seems to be a phrase used colloquially or informally, particularly in internet language or slang. The term likely originates from combining the verb "am" (the first-person singular form of the verb "to be") with the adjective "smooth". The word "smooth" means having an even or level surface, or being free from roughness or friction. In this context, "am smooth" is often used to imply being cool, calm, effortless, or having a confident demeanor. However, it is important to note that "am smooth" does not have an official etymology or historical origin as it is generally a contemporary slang phrase.