Denshi Jisho — Online Japanese dictionary

Couldn't find anything for 阻む~, so trying 阻む instead.

阻む はばむ to keep someone from doing; to stop; to prevent; to check; to hinder; to obstruct; to oppose; to thwart
Common word, Godan verb with mu ending 

You can also

Look up kanji details for 阻む.

Try a Yahoo Jisho search for 阻む .
Try a Goo Jisho search for 阻む .
Try a Google search for 阻む .