Cite
 
gonk: /gonk/, vi.,n.

1. [prob. back-formed from gonkulator.] To prevaricate or to embellish the truth beyond any reasonable recognition. In German the term is (mythically) gonken; in Spanish the verb becomes gonkar. “You're gonking me. That story you just told me is a bunch of gonk.” In German, for example, “Du gonkst mich” (You're pulling my leg). See also gonkulator.

2. [British] To grab some sleep at an odd time; compare gronk out.