Correct spelling for the English word "tailest" is [tˈe͡ɪləst], [tˈeɪləst], [t_ˈeɪ_l_ə_s_t] (IPA phonetic alphabet).
The word "tailest" is derived from the Old English word "tæl", which means "a story" or "a spoken account of an event". In Old English, the superlative form of "tæl" was "taelest", meaning "most telling" or "most significant". Over time, this form evolved into "tailest", while still maintaining a similar meaning. However, it is worth noting that "tailest" is an antiquated form and not commonly used in modern English.