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1.
literally: definitely totally

def tots is a play off of the abbreviations of definitely (def) and totally (tots).
def tots can be used as a replacement for definitely, totally, or absolutely, and can also be used to emphasize an adjective.
EXAMPLE ONE
p1: that guy is so hot!!
p2: uhhh, def tots.

EXAMPLE TWO
p1: how was your weekend?
p2: it was def tots awesome!
by whyareallthenamestaken August 10, 2008