Green’s Dictionary of Slang

1. (US, also honk on) to talk loudly in a boastful manner.

1906		‘O. Henry’ ‘The Skylight Room’ in Four Million (1915) 48: She would honk loudly the word ‘Clara,’ she would show you her back, and march downstairs.
1970		E. Thompson Garden of Sand (1981) 431: ‘Come back here!’ the barkeeper honked.
1989		T. Blacker Fixx 175: Red-faced youths, honking with delight.
1995		J. Stahl Permanent Midnight 279: He made a point of mentioning the Oxford thing, and honked on it constantly.
2000		T. Udo Vatican Bloodbath 108: The chinlessly honking offspring of Britain’s genetically defective landed aristocracy.

2. to vomit.

1984		A. Sayle Train to Hell 116: Bring some plonk but don’t honk.
1995		J. Cameron Vinnie Got Blown Away 15: Dickheads out of Loughton honk up their rump steaks all over the gutter.
2010		L. Berney Gutshot Straight [ebook] She felt like she was going to hornk [sic] up her lunch, she was so scared.

3. to snore.

2004

T. Winton Turning (2005) 150: That night in bed [...] Max honked and farted beside her.