To lack the courage to do something; to be afraid to do something

to exceed a limit; to overstep a boundary; to surpass or go out of sequence

(literary) a boundary or restricted area; usually used in the phrase 不敢越雷池一步 bù​gǎn​yuè​léi​chí​yī​bù, meaning one must not overstep the mark

The distance covered by one stride while walking; often used to describe a very short distance or time.