When you are either too lazy to prepare a complete lunch, too broke to afford one, or there is simply nothing else to eat but chips*.
Similar to "chip dinner", but at lunch time.

*Not to be confused with Nachos, which is actually a meal.
"What are you having for lunch today?"

"Payday isn't for 3 more days, and all I had at home was this half bag of Doritos. Looks like chip lunch for me."
by Jimmydoorlocks February 1, 2010
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