Wiktionary
petty officer second class
n. 1 (context Canada Navy English) A non-commissioned officer in the Canadian Forces Maritime Command, ranking above master seaman and below petty officer first class. 2 (context US Navy English) A non-commissioned officer in the United States Navy and United States Coast Guard, ranking above petty officer third class and below petty officer first class.
Usage examples of "petty officer second class".
There was also a petty officer second class, but Sturgeon didn't recognize the rating symbol on his rank insignia.