executive officer (n.)

• acolyte
• adjutant
• advocate
• agent
• aid
• aide
• aide-de-camp
• aider
• alternate
• archon
• assistant
• attendant
• attorney
• auxiliary
• backup
• brigadier
• captain
• champion
• chancellor
• coadjutor
• colonel
• commandant
• commander
• dean
• deputy
• dummy
• exec
• executive
• exponent
• figurehead
• general
• generalissimo
• help
• helper
• helpmate
• helpmeet
• lieutenant
• locum
• magistrate
• major
• management
• marshal
• officer
• official
• paraprofessional
• pleader
• prefect
• president
• prexy
• procurator
• provost
• proxy
• representative
• second
• secondary
• secretary
• servant
• sirdar
• stand-in
• subaltern
• sublieutenant
• substitute
• surrogate
• treasurer
• understudy
• vicar
• vice
• vicegerent
• warden