Thayer's Greek Lexicon

 1. to strike against
  1) of those who strike against a stone or other obstacle
in the path, to stumble
  2) to strike one's foot against a stone
1b1. i.e. to meet with some harm;
  3) to rush upon, beat against
  4) to be made to stumble by a thing
1d1. i.e. metaph. to be induced to sin