A "lieutenant commander" is a rank in the military. It is someone who is in a leadership position and has authority over a group of people, but they are below the rank of commander. Full definition
She is a former lieutenant commander in the U.S. Navy's Judge Advocates program. (syracuse.com)
She held the rank of lieutenant commander in the United States Navy, and from 2001 to 2008, she was the associate dean of students at Syracuse University. (104.236.62.190)
Croci, an attorney, former Navy lieutenant commander and onetime White House military aide, is a significant player on national security issues as chairman of the Senate Veterans, Homeland Security and Military Affairs Committee. (newsday.com)