adj. Never tiring or lacking energy; without rest; without slowing.
The Century Dictionary and Cyclopedia
Not flagging; not drooping; maintaining strength or spirit; sustained; as, unflagging zeal.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. showing sustained enthusiastic action with unflagging vitality
adj. unceasing
Word Usage
"Defence lawyer Sean May, who asked for three to six months in jail, said his remorseful client has no criminal record, welcomes treatment and has the "unflagging" support of his wife"