Praise which has no value/of less value than had it come from a more esteemed person.
I.e. when Donny Osmond gave out the first ten of Strictly Come Dancing 2014 as a guest judge, it wasn't the same as receiving the first ten of the series from one of the permanent judges.
Someone who acts and tries to be someone of a higher class or higher age. Commonly seen in freshman, who act like an upper classmen by wearing the senior colors on class color day when they are a freshman. Someone who acts this way in order to get attention and respect from the "older kids".
A Donny (adjective) : Dude Blake, why are you wearing senior colors. Stop being a Donny
A Donny : Rebecca, you freaking Donny. Stop going after seniors.
When you take a sip of a drink and it goes down the wrong way, causing excessive coughing and the inability to speak. Often happens to Donna (referred to jokingly as “Donny” by her sons), usually when drinking water, which is who the term was coined after.