en·sign (ĕnsən, -sīn′)
1. A national flag displayed on ships and aircraft, often with the special insignia of a branch or unit of the armed forces.
2. A standard or banner, as of a military unit.
a. A commissioned rank in the US Navy or Coast Guard that is below lieutenant junior grade.
b. One who holds this rank or a similar rank in another military organization.
4. A badge, emblem, or token of power or authority.
[Middle English ensigne, from Old French enseigne, from Latin īnsignia, insignia; see INSIGNIA.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.