indefatigable(extremely persistent and untiring) adjective [UK: ˌɪn.dɪ.ˈfæ.tɪ.ɡəb.l̩] [US: ˌɪn.də.ˈfæ.tɪ.ɡəb.l̩]Mary is an indefatigable defender of the rights of indigenous communities. = Mary es una infatigable defensora de los derechos de las comunidades indígenas.
tireless(indefatigable) adjective [UK: ˈtaɪə.ləs] [US: ˈtaɪər.ləs]Your tireless efforts deserve thanks. = Tu trabajo infatigable amerita las gracias.
unstinting(generous and tireless with one's contributions) adjective [UK: ʌn.ˈstɪnt.ɪŋ] [US: ʌn.ˈstɪnt.ɪŋ]