1
general::
Phrase(s): take a turn for the better
to start to improve; to start to get well. • She was very sick for a month; then suddenly she took a turn for the better. • Things are taking a turn for the better at my store. I may make a profit this year.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Improve, as in We thought she was on her deathbed but now she's taken a turn for the better. The antonym is take a turn for the worse, meaning "get worse, deteriorate," as in Unemployment has been fairly low lately, but now the economy's taken a turn for the worse. This idiom employs turn in the sense of "a reversal," a usage dating from about 1600.
American Heritage Idioms