my brother's like that. he tries to show off that he has a large vocab and always uses huge ass words in normal conversation when there is no need for them.

even worse people who try to use big words in conversation to sound smart and wind up fucking up the meaning or mis-pronouncing. i knew this one kid who would always try to sound as if he was smarter than he really was by doing that and i when i would correct him (because i didn't want him going around using words he didn't know or couldn't pronounce and looking like a jackass) he would just tell me he was right and i was wrong. um...i'm a writer so i have a pretty decent vocab!