kibble

Unknown; the verb is first attested in 1790 in William Marshall’s dictionary of agricultural provincialisms, of Shropshire dialect, perhaps variant of chip or derived from kibble (“an iron bucket”). The noun is derived from the verb.

The Transformers fandom etymology 1, noun sense 4 was coined by Usenet user Lizard in February 1996, after etymology 1, noun sense 1 (“animal feed”); etymology 1, noun sense 5 is by extension.