Synonyms of tireless

Adjective

1. indefatigable, tireless, unflagging, unwearying, energetic (vs. lethargic)

usage: showing sustained enthusiastic action with unflagging vitality; "an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence"

2. hardworking, industrious, tireless, untiring, diligent (vs. negligent)

usage: characterized by hard work and perseverance

Definition and meaning of tireless (Dictionary)