Definition from Wiktionary, the free dictionary
A-4 (plural A-4s)
- (military) Skyhawk single engine attack aircraft.
- (military) Air material and supply officer.
2001, Today's Logistics:
- Deployed to a provisional air base squadron as the LG and serving as an A-4 officer...
- (military) Material and supply section of an Air Force staff.
1944, AAF The Official Guide To The Army Air Forces:
- A-4 or S-4, performs all staff functions pertaining to supply and maintenance.