Not able to be shaken; firm, solid, resolute(adjective)
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Use "unshakeable" in a sentence
"I am sure, have joined with me in unshakeable faith that this crucial test will be met; that the searing lessons of this latest war and the promise of the United Nations Organization will be the cornerstones of a new edifice of enduring peace and the guideposts of a new era of human progress."
"And Feste, echoing the criticism of these decisions, approvingly recalled the unshakeable instinct of many of the WWII generation to defend the incarceration of Japanese Americans:"
"They see U.S. support for Israel - which Obama declared as "unshakeable" - as underpinning the refusal of Prime Minister Benjamin Netanyahu's government to halt the construction of Jewish settlements on lands that the Palestinians claim for their future state."