energetic
abiding
ardent
assiduous
constant
continuing
continuous
determined
diligent
dogged
enduring
faithful
fervent
hard
hardworking
immutable
inalterable
indomitable
industrious
inexhaustible
insistent
invincible
laborious
lasting
loyal
never idle
never-tiring
obstinate
painstaking
patient
patient as Job
permanent
perseverant
persevering
persistent
persisting
pertinacious
plodding
plugging
preoccupied
rapt
relentless
remaining
resolute
sedulous
single-minded
sleepless
enterprising
intrepid
sagacious
self-sacrificing
skilful
strenuous
tireless
untiring
zealous