A dull tongue
Chinese idiom, Pinyin is ch ǐ Lu ò sh é D ù n, which means that old people lose their teeth and can't speak clearly. From a dream of Red Mansions.
The origin of Idioms
The second chapter of a dream of Red Mansions: "the old monk is deaf and faint, and his tongue is blunt. What he answered is not what he asked."
Analysis of Idioms
Antonym: glib
Idiom usage
Used as a predicate or attributive; used of the elderly.
A dull tongue
have a preconceived idea at heart - xiōng yǒu qiū hè
Callose shoulder and callous foot - zhī jiān jiǎn zú