In-universe, Kirayoshi is named after Kira Nerys, one of his gestational mothers, a Bajoran alien (note: in Bajoran culture, the surname comes first - her given name is Nerys). Assumably, his name is a compound of the names Kira (which, while not given a meaning in-show, coincides with the Japanese ideologue きら, which refers to twinkling, like that of the stars) and Yoshi (from Japanese 吉 (yoshi) meaning "good luck", 義 (yoshi) meaning "righteous", or 良 (yoshi) meaning "good, virtuous, respectable", as well as other kanji with the same reading.)
Assumably, his name is a compound of the names Kira (which, while not given a meaning in-show, coincides with the Japanese ideologue きら, which refers to twinkling, like that of the stars) and Yoshi (from Japanese 吉 (yoshi) meaning "good luck", 義 (yoshi) meaning "righteous", or 良 (yoshi) meaning "good, virtuous, respectable", as well as other kanji with the same reading.)