It means obstacle, setback, difficulty, impediment, unforeseen, fall, stumble, stumble. It also means mistake, lack, slip, error, mistake.
1st. That which hinders or retards the pace, the advance; which can even cause a fall. In the broadest sense, it is an error, a difficulty, a slip or setback in some task. 3º_ Inflection of the verb to stumble . See verbs/stumbling block.