unflagging
adjective
[ ʌnˈflaɡɪŋ ]
• tireless; persistent.
• "his apparently unflagging enthusiasm impressed her"
Similar:
tireless,
persistent,
dogged,
tenacious,
determined,
resolute,
staunch,
single-minded,
unremitting,
unrelenting,
unswerving,
unfaltering,
unfailing,
unending,
zealous,
