Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You try to obstruct a woman coming your way (see kanji). As she gets close, she roars, "I am Sama(n)tha!" (さまた) You shall let me pass!" You don't argue with Samanthas. Get out of her way!
I heard that company is trying to hamper Tofugu's success.
You should get rid of things that obstruct productivity.
I don’t understand why people try preventing aliens from reaching the earth.