老掉牙 lǎodiàoyá decrepit Origin Definitions Defs Strokes Stroke Words Sentences Sents Showing: outdated All meanings 2 lǎodiàoyá 2 decrepit 1outdated 1 1 sentence for 老掉牙 (lǎodiàoyá — outdated) 这种老掉牙的理论早已被现代科学推翻了。 zhè zhǒng lǎodiàoyá de lǐlùn zǎoyǐ bèi xiàndài kēxué tuīfān le. This obsolete theory has long been overturned by modern science. Source: Dong Chinese Dictionary