Law Cadet
A person neither trained nor qualified in law who, having had a brief acquaintance with some legal matter or other, professes him or herself an expert on all things legal.
"I didn't realise Adam was a lawyer."
"He isn't. He just got sued. Suddenly he's Justinian."
"Ah, another Law Cadet!. Great!"
"He isn't. He just got sued. Suddenly he's Justinian."
"Ah, another Law Cadet!. Great!"