- sedulous (adj.)
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- 1530s, from Latin sedulus "attentive, painstaking, diligent, busy, zealous," probably from sedulo (adv.) "sincerely, diligently," from sedolo "without deception or guile," from se- "without, apart" (see secret) + dolo, ablative of dolus "deception, guile," cognate with Greek dolos "ruse, snare." Related: Sedulously; sedulousness.