an enlisted person, as a sergeant or corporal, holding any of various ranks below commissioned or warrant officers.
Origin of noncommissioned officer
First recorded in 1695–1705
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(in the armed forces) a person, such as a sergeant or corporal, who is appointed from the ranks as a subordinate officer
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012