/ əˈsɪdjuəs; NAmE -dʒuəs/ adjective
( formal ) working very hard and taking great care that everything is done as well as it can be
SYN diligent
► as·si·du·ity / ˌæsɪˈdjuːəti; NAmE / noun [ U ]
► as·sidu·ous·ly adverb
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WORD ORIGIN
mid 16th cent.: from Latin assiduus , from assidere be engaged in doing from ad- to, at + sedere sit, + -ous .