The phrase "am extant" is spelled as /æm ɪkˈstænt/. The first sound is the short "a" sound followed by the "m" sound. The stress falls on the second syllable, on the "ex" sound. The "t" sound at the end is silent, which can be confusing for English language learners. The word "extant" means currently existing or still in existence. This phrase is often used to emphasize that something is still present or available, despite the passage of time.
The phrase am extant is not a standalone word with a specific etymology. Am is the first person singular form of the verb to be in the present tense. Extant is an adjective that means still in existence or currently existing.