WordNet sense 1 (pull back or move away or backward):

recede, retire, retreat, withdraw, move back, pull away

WordNet sense 2 (use a surgical instrument to hold open (the edges of a wound or an organ)):

retract

WordNet sense 3 (pull back the sling of (a bow)):

draw

WordNet sense 4 (make a retreat from an earlier commitment or activity):

crawfish, back out, back away, crawfish out, pull in one's horns