Definition of "unflagging"

He went on kissing her with unflagging industry, while she remained limply in his arms, in a species of satisfied trance.

1930, Norman Lindsay, Redheap, Sydney, N.S.W.: Ure Smith, published 1965, page 122

He writes of locomotive design, maintenance, passenger timetables, the structure of freight services, supervision and organisation, with unflagging enthusiasm, which comes across to us in a most readable book.

1959 May, “New Reading on Railways: British Railways Today and Tomorrow. By G. Freeman Allen. Ian Allan. 25s.”, in Trains Illustrated, page 271

The 2001 photo was strangely and powerfully similar to the World War II flag raising because both photos captured a heroic deed of courage, grit, teamwork, and unflagging patriotism at a historic moment marked by the darkness of the threat against us.

2008, Karlyn Kohrs Campbell with Susan Schultz Huxman, The Rhetorical Act: Thinking, Speaking and Writing Critically‎, page 265

His words mattered. He pledged “our unwavering and unflagging commitment to Ukraine’s democracy, sovereignty, and territorial integrity.”

2023 February 20, Eliot A. Cohen, quoting Joe Biden, “Biden Just Destroyed Putin’s Last Hope”, in The Atlantic‎