shave + tail
shavetail (plural shavetails)
- (US) An inexperienced person, especially a newly-commissioned military officer.
- 1962 (2006), Joseph Commings, "The X Street Murders", The Mammoth Book of Perfect Crimes & Impossible Mysteries
- Yass. I never got above the rank of shavetail. We were the dogfaces who gave ’em hell at Chateau Thierry.