Adjective. To have a tendency to steal words out of other people's mouths.
"Lexicon," meaning vocabulary or word base, and
"Kleptomaniac," meaning a person who has a natural urge to steal, even without need or profit.
Joe & Bill Together: Why did you do that?
Joe: Hey! You just stole the words out of my mouth, you lexiconically kleptomaniacal freak!