refrain from (doing something)
To make a considered, conscious effort not to do something. I ask everyone to refrain from asking questions until the end of the presentation. Please refrain from talking while you are in the library.
refrain from something
to hold back from doing something; to choose not to do something as planned. I wish you would refrain from shouting. Please refrain from hollering.
refrain from
v. To make a conscious decision not to do something: All passengers must refrain from smoking during the flight.