Green’s Dictionary of Slang

honk on v.

also honk off
[? honk (it on) v.]

1. (US campus) to go away, to leave one alone.

[US]G. Underwood ‘Razorback Sl.’ in AS L:1/2 61: honk on vi 1: Depart, leave 2: Leave one alone.
Univ. Tenn. student: Honk off means about the same as fuck off! shove it! [HDAS].

2. see honk v.1 (1)