The Jargon File (version 4.4.7, 29 Dec 2003):
geef v. [ostensibly from ?gefingerpoken?] vt. Syn. mung. See also blinkenlights .The Free On-line Dictionary of Computing (30 December 2018):
geef (Ostensibly from "gefingerpoken") mung. See also blinkenlights. [Jargon File] (1995-01-18)