अटल (en. Implacable)

Indeed, due to the fact that the U.S. armed forces were drawn into an implacable military-technological confrontation, their preparation for combat encounters with the unexpected use of technological solutions may be as important as the development of the new "black" features.

An implacable fighter for human rights during the existence of apartheid, for which he spent 27 years behind bars.

Tipu Sultan was considered an implacable enemy of the British East India Company.

Tipu was a ruler of the erstwhile kingdom of Mysore and considered an implacable enemy of the British East India Company.

The regime is so wedded to certain ideological principles - including the export of the Islamic Revolution through proxy warfare and the subversion of fellow Muslim-majority countries, implacable opposition to Israel and the United States, and stringent social controls that restrict the rights of women - that it cannot endure any competing ideas.

The theory of permanent revolution, and the implacable struggle put up by Trotsky inside the Comintern and the Soviet Union, summarised in the 1938 program of the Fourth International, founded by Trotsky, guides and enriches our experience of the last century.

He was considered an implacable enemy of the British East India Company.