Correct spelling for the English word "Astond" is [ɐstˈɒnd], [ɐstˈɒnd], [ɐ_s_t_ˈɒ_n_d] (IPA phonetic alphabet).
The word "astond" appears to be a variant or archaic form of the word "astound".
The etymology of "astound" can be traced back to Old English. It is derived from the combination of the prefix "a-" (meaning "completely" or "thoroughly") and the word "stound" (meaning "a sudden, sharp noise, or shock"). "Stound" itself is related to the Old Norse word "stund", which also means "a sudden shock".
Over time, the word "astound" evolved from its Old English form, with the prefix "a-" losing its original intensifying force, and "stound" transforming into the familiar "-ound" ending associated with many verbs in English, such as "found" or "wound".