屠龍之技tú lóng zhī jìthe art of butchering dragons—unpractical skill of great attainments; an art of a high order but of little value
? 及至學(xué)成～，不但無(wú)所用，且無(wú)可語(yǔ)者。(黃宗羲《敘陳言揚(yáng)勾股述》) As he finished learning the refined art,he found that it was not only useless but there was nobody that he could talk to about it. 屠龍之技tú lónɡ zhī jì屠：宰殺。比喻雖然有很深的造詣但卻不實(shí)用的技能。useless skill, a little value skill |