CO-OPERATE

\kˈə͡ʊˈɒpəɹˌe͡ɪt], \kˈə‍ʊˈɒpəɹˌe‍ɪt], \k_ˈəʊ_ˈɒ_p_ə_ɹ_ˌeɪ_t]\
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1899 - The american dictionary of the english language.
By Daniel Lyons
 
1919 - The Concise Standard Dictionary of the English Language
By James Champlin Fernald