that quiet kid that always gets left behind especially in dangerous situations

A timmy is that one kid to break something at a party. He spills his drink at every dinner. If there is fire around, he will put his finger in it. If there is a knife around he will start cutting things.

Refers to a result of plus 2 to par (or worse ) on a golf hole (aka double bogey, triple bogey, etc.). Also, a player who has 3 or more putts on a hole has committed a Timmy.

Origin - Timmy is a guy that bailed on a golf commitment in the 11th hour. A scoundrel.

Timmy is an average kid who no one understands, his mom dad and baby sitter all give him commands

From South Park cartoons, a kid who is mentally handicapped.
retard

A chain of Canadian coffee shops that sport the name of hockey legend, Tim Horton. Found all over Canada, Tim Horton restaurants are best known for their coffee and small whole doughnuts called, Timbits.

A reference to a mentally challenged south park character who is only able to say his own name.