diligent Play adjectiveHaving or showing care and conscientiousness in one's work or duties. SYNONYMS activeassiduousattentivebusycarefulcommittedconscientiousconstantdedicateddoggeddrivenearnestexactinghard-workingheedfulindefatigableindustriousintentlaboriousmeticulouspainstakingparticularperseveringpersistentpertinaciousploddingpunctiliousrigorousseduloussloggingstudioustenaciousthoroughtirelessunflagginguntiringzealous