1 definition by GingerBacon

The term used when someone driving assumes it is okay to indicate or directly change lanes before looking in their mirrors.
This confident action was named after Gandalf from the Lord of the Ring films. Assuming that he or she is the superior on the road and that others on it "shall not pass", hence the name, Gandalfing.
It is usually subtly mentioned by a passenger when they notice the driver committing this.
"Gandalf" - said under your breath when you notice them do it.
Alternatively, "are you gandalfing?" or,
"did you just Gandalf?"
by GingerBacon April 6, 2014
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