(FORMAL) to teach someone something; to show someone how to do something
The school board will develop a course of study to instruct high school students on parental skills and child development.
(mainly BrE) when a client authorises a solicitor or barrister to act on his or her behalf; when a solicitor gives information about a case to a barrister to present in court
They had instructed a solicitor to pursue a negligence claim.
to formally tell someone what to do or what not to do
The jurors were instructed not to use a computer, cellular phone or other electronic device with communication capabilities.