Correct spelling for the English word "selenoid" is [sˈɛlənˌɔ͡ɪd], [sˈɛlənˌɔɪd], [s_ˈɛ_l_ə_n_ˌɔɪ_d] (IPA phonetic alphabet).
The word "selenoid" is derived from the combination of two Greek words: "selene" (σελήνη), meaning "moon", and "eidos" (εἶδος), meaning "form" or "shape". Thus, "selenoid" literally means "moon-shaped" or "resembling the moon". The term is often used in various scientific fields to describe objects or phenomena that have a crescent or circular shape similar to that of the moon.