The tip of the chopsticks are burnt.
Previous to the edge is what's right before the edge is over. That's the tip of the edge. It's also a word used to describe the latest (technology, etc), because it's on the bleeding edge, so to speak. The tip!
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.