steadfast
adj.staying loyal and firm in your beliefs or actions, even when things get difficult. You use this to describe someone who does not change their mind or give up.
adj.firm and unwavering in purpose, loyalty, or resolve. Often used to describe personal character or commitment in the face of adversity.
“She remained a steadfast friend during my hardest years.”
“Despite the economic downturn, the company remained steadfast in its commitment to environmental sustainability.”
“The leader's steadfast refusal to compromise on core principles eventually earned the respect of even her most vocal political opponents.”
Typically used attributively before a noun or predicatively after a linking verb like 'remain' or 'stay'.
“Burnham told Zelenskyy during their meeting that there would be “no change in the UK’s steadfast support” for Kyiv .”
“The Madrid club's steadfast refusal to sanction the 26-year-old's dream move to the Spotify Camp Nou has led to one of the most rancorous public falling-outs in recent memory.”
From Middle English stedefast, from Old English stedefæst, from Proto-Germanic *stadifastuz, equivalent to stead (“place; spot; position”) + fast (“firm; fixed”). Cognate with Middle Dutch stedevast (“steadfast”), Icelandic staðfestur (“steadfast”), Danish stedfast (“firmly attached, secured”), Danish stadfæste (“to confirm; ratify”), Norwegian Bokmål stadfeste (“confirm, ratify; establish”), Swedish stadfästa (“to confirm; establish”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.