Diligent synonyms such as attentive, active, and assiduous. Diligent is an adjective, and its antonyms are lazy and casual. Additionally, here are 38 synonyms for diligent and words similar to it.
Active, assiduous, attentive, busy, careful, committed, conscientious, constant, dedicated, dogged, driven, earnest, exacting, hard-working, heedful, indefatigable, industrious, intent, laborious, meticulous, painstaking, particular, persevering, persistent, pertinacious, plodding, punctilious, rigorous, sedulous, slogging, studious, tenacious, thorough, tireless, unflagging, untiring, and zealous.