Refers to an article of clothing that is entirely too small for the individual wearing it; i.e. A "pham shirt" or "pham pants". 'Pham' derives from 'fam', as in 'family', referring to the fact that the article of clothing belongs to a younger or smaller family member.
"Wow, look at Luke's pham shirt! He's probably trying to show off his biceps for Janie, what an arse."
"Dude, nice pham khakis. God, they come halfway up your shins!"