The Greek lexeme euteos should be understood primarily as an adverb of quality, rather than regularly be taken as an adverb of time in the New Testament. Three problematic passages with euteos will be discussed. They are 3 John 14, Galatians 1:15-17, and a variant reading in Acts 14:8-10. As background to this discussion the meaning of the adjective euteos is considered, as well as its use in various derivative and compound words. Next the formation of adverbs of manner and their place in the Greek sentence or phrase is envisaged. Four meanings of euteos as an adverb of quality, drawing on extra-biblical and New Testament sources, are identified before proceeding to discuss the three problematic passages, indicating how euteos is to be understood and translated.