Past lunchtime....or....a latish lunch
"Dude, I gotta go, it's lunchthirty" ("Gotta go, It's past my lunchtime!")

or

"So we'll meet you guys at Joe Schmoe's Bar & Grill around lunchthirty on Friday?" ("we'll meet for a late lunch at Joe's?")
by Generica McPlainwrap June 14, 2007
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