material (such as rocks, earth, bamboo etc) used to hastily repair a dike / (literary) door bar (vertical bar used to prevent the horizontal movement of a door bolt)
千里之堤，溃于蚁穴
qiān lǐ zhī dī , kuì yú yǐ xué
an ant hole may cause the collapse of a great dike (idiom) / huge damage may result from a moment's negligence
土牛
tǔ niú
clay ox / mound of earth on a dike (ready for emergency repairs)
(dialect) an opening at the bottom of a dike for letting water in or out / small channel across a river embankment / (used in place names) / Taiwan pr. [dou1]
bà