暗箭难防 (暗箭難防) ànjiàn nán fáng

ànjiàn nán fáng set phrase an attack by stealth is hard to defend
Domain: Idiom 成语
Notes: (Guoyu '暗箭難防'; Mathews 1931 '暗箭難防', p. 6)

Also contained in

明枪好躲，暗箭难防 、 明枪易躲，暗箭难防