tireless

adjectives

showing sustained enthusiastic action with unflagging vitality
"an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence"
indefatigable, tireless, unflagging, unwearying
is derived from
tirelessness
characterized by hard work and perseverance
hardworking, industrious, tireless, untiring
is derived from
tirelessness