Teacher's deg.
Else clues• Blew hot air
• Coll. degree
• Pretended to know a lot, briefly
• Spoke above one's pay grade
• Spoke with false authority
• Talked a big game, for short
• Talked beyond one's expertise, as it were
• Talked confidently beyond one's expertise
• Teacher-to-be's deg.
• Teaching deg.
• Teaching degree
• Told a total lie