Emily Dickinson Lexicon

AS-SID'U-OUS, a. [L. assiduus, from assideo, to sit close, ad and sedeo; Eng. to sit; Sax. sittan, settan.]

1. Constant in application; as a person assiduous in his occupation.
2. Attentive; careful; regular in attendance; as, an assiduous physician or nurse.
3. Performed with constant diligence or attention; as, assiduous labor.