verbs
turn abruptly and face the other way, either physically or metaphorically
"He turned around to face his opponent"; "My conscience told me to turn around before I made a mistake"
improve dramatically
"The new strategy turned around sales"; "The tutor turned around my son's performance in math"
is a type of (narrower)
to make better
"The editor improved the manuscript with his changes"
improve significantly; go from bad to good
"Her performance in school picked up"