To prevent two people from hugging, usually killing the moment. Smaller version of a cock block
John sees his girlfriend after 5 years, he runs to her, but Dan jumps in and hug blocks John.
by Joethemale June 24, 2010
the equivalent to a cockblock but for hugs
man, his big ass backpack totally hugblocked me!
by mreowww1 September 14, 2011