Normally when people say RAWR it is plainly interpreted as just a crazy person shouting the word RAWR (If it's even a word). However, there are in fact 3 different kinds of RAWRs.
First off there is the lion RAWR. If you say RAWR while speaking lioon you are telling everyone around you "FEAR ME!!!"
Next there is the dinosaur RAWR. If you say this RAWR to someone tyou are telling them that "I love you" so watch out who you say RAWR to when speaking dinosaur.
And finally there is the human RAWR which is a way of saying "RAWR!"