rear admiral (lower half)

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun US, military, nautical A commissioned officer in the United States Navy, Coast Guard, NOAA Corps, or PHS Corps of a grade superior to a captain and junior to a rear admiral (upper half). A rear admiral (lower half) is equal in grade or rank to an Army, Marine Corps, or Air Force brigadier general.
• noun US, military, nautical A naval officer of equivalent grade or rank in the navy of other countries, such as commodore.