如火如荼 [ㄖㄨˊ ㄏㄨㄛˇ ㄖㄨˊ ㄊㄨˊ; ru2 huo3 ru2 tu2] lit. white cogon flower like fire (idiom); fig. a mighty army like wildfire daunting and vigorous (momentum) flourishing magnificent ◄ ►