Assiduous
ASSID'UOUS, adjective [Latin assiduus, from assideo, to sit close, ad and sedeo; Eng. to sit.]
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.