Pronunciation: [sˌiːkˌe͡ɪˌɛstˈiː] (IPA)
Correct spelling for the English word "ckst" is [sˌiːkˌe͡ɪˌɛstˈiː], [sˌiːkˌeɪˌɛstˈiː], [s_ˌiː_k_ˌeɪ_ˌɛ_s_t_ˈiː] (IPA phonetic alphabet).
Correct spelling for ckst