gainsay
/ˌgeɪnˈseɪ; ˌɡen`se/ v
(pt, pp gainsaid/ -ˈsed;-`sɛd/) [Tn]
(arch 古) (usu in negative sentences or questions 通常用於否定句或疑问句) contradict (sb/sth); deny (sth) 反驳（某人[某事物]）; 否认（某事物）
There's no gainsaying his honesty, ie We cannot deny that he is honest. 他为人诚实无可否认.