Any guy or girl that you fuck with on the side while in a relationship, anyone other than your significant other. Side sauce commonly does not know you are in a relationship or thinks that you are in a relationship with them.
A golf term coined by renowned golfer Phil Mickelson. Side sauce is that special oomph added to a shot to ensure that it will go in. Usually used in a playful, cocky manner. Can also be used in a general manner to describe a shot made with a lot of finesse and precision that will definitely go in.
"Gonna add a little side sauce to this chip shot. Baby's going right in."
"Pins on the left, and there's a ridge from the right, so the ball will feed to it. So I'm going to side sauce one in there from the right." -Phil Mickelson on his golf game
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".