Pronunciation: [ɹəbˈʌst͡ʃuːəs] (IPA)
Correct spelling for the English word "robustuous" is [ɹəbˈʌst͡ʃuːəs], [ɹəbˈʌstʃuːəs], [ɹ_ə_b_ˈʌ_s_tʃ_uː_ə_s] (IPA phonetic alphabet).