A weird unattractive word used to name (and/or describe) a certain person in your contact list. In most cases, this person will be the reason the block button was invented.
"You need to put his name in your phone as a weird word that is unattractive... like grundle."
by teatimetay March 10, 2014
Grundles are brown cave-dwelling creatures from the My Little Pony movie. They look like monsters to most people, but, as they constantly reassure Baby Licketysplit and Spike the dragon, "Grundles good!" They are helpful, friendly creatures. Interestingly, Danny DeVito played the Grundle Leader in the movie.
Grundles not monsters! Grundles good!
by Jezani May 10, 2009