social osmosis
Where a person adopts the catchphrases of another person when they start hanging out with them.
Person 1- "It's weird, Jim has been using the word 'dude' a lot lately."
Person 2- "Yeah he has been hanging out with Sue and that is her word."
Person 1- "Oh he has a case of social osmosis."
Person 2- "Yeah he has been hanging out with Sue and that is her word."
Person 1- "Oh he has a case of social osmosis."