Related Clues:
- Brief blast on a horn
- Pat one's own back
- ... drive -- undesirably let off
- Dress up showing swagger
- Warning by driver heading left or right
- With 18-Across, what a boastful guy might do
- Show off backing of costume ...
- Model train sound
- Honk horn — in both directions
- Be a whistleblower
- Casually play a flute
- Blow on a horn
- Blast back and forth
- Show off reversible clothes
- Bring-and-__ (show-and-tell)