{v. phr.} To relieve someone's anxieties; reassure someone. * /"Lef me set your mind at rest about the operation," Dr. Vanek said. "You'll be back on your feet in a week."/
SET ONE'S MIND AT REST
Meaning of SET ONE'S MIND AT REST in English
Slang English vocab. Английский сленговый словарь. 2012