adamant/ˈædəmənt/
adj.强硬的;坚定不移的;固执的I am adamant about it.我坚持这一点。
He was adamant in his determination to punish the corrupt officials.他下了决心,坚决惩治那些贪官污吏。
He's so adamant that however hard I tried to persuade him to join us he did not change his mind.不管我怎样劝他跟我们一起干,他毫不动摇,不肯改变主意。