0 If someone has untiring energy, interest, or enthusiasm, their energy, interest, or enthusiasm never becomes weaker:
1 (esp. of qualities such as energy, interest, and enthusiasm) never weakening:
Without Tony’s untiring enthusiasm, this campaign would not have succeeded.
With untiring zeal he ransacked the archives, exhumed scores of documents and edited many of them.
His whole-hearted devotion to that cause, and his untiring efforts to promote it, led in some degree to the breakdown of his health.
Sharp's untiring energy in song collecting had made up for his comparatively late advent into the ranks of the collectors.
In spite of every discouragement and every form of futile opposition, he has persisted with untiring energy.
We are continuing to press for early work on enforcement measures in case the secretary general's untiring efforts are not successful.
We can do that with confidence, and we must do it with untiring commitment - and no one will stop us.
I pay tribute to her untiring efforts to have his conviction reviewed because of the many disturbing discrepancies in the case.
It was an impressive story of untiring work to try to bring about a peaceful solution to this intractable problem.