To "Understand",is to Dig(like it or not) what a person is saying.
To "underdig" is a total comprehension of what someone is sayin'.
That's some California Bay Area Lingo...
brought to you by The E Forty (E40) himself... get the book learn the lesson..All others are posers. please believe
Make sure you Underdig what I'm saying, before I have to put my hands on you.
-Used widespread throughout urban neighborhoods. Although the origins are unknown, Def Jam/ Roc-A-Fella/ Thugged Out Militainment recording artist N.O.R.E. aka Noreaga is credited for makeing the term mainstream.