If you extract your waist you're pulling your body from the situation and trying to escape. What a coward.
Or, picture a little kid trying hiding behind their mom. Try to extract them from behind their mom's waist. They're holding on! They don't want to come out. What a coward of a child!
There are lots of different kinds of cowards.
This word uses the kun'yomi readings for both kanji, which you've learned already. Go you!
There are too many coward employees who resign before being promoted to management.