The term "club side" refers to a particular area or location on a golf course. It is often used in reference to the positioning of a golfer's ball, particularly when discussing where their shot has landed relative to obstacles such as bunkers, water hazards, and trees.
In this context, "club side" means that the ball is on the part of the fairway or green that corresponds with the club being used for a particular stroke. For example, if a golfer hits their drive from the tee using a driver, they will want to aim towards the "driver side" of the fairway in order to have the best chance at hitting the ball as far as possible. Similarly, when approaching the green, golfers may be advised to hit their approach shot with a particular club - such as a wedge or putter- and so they will want to aim towards the "wedge side" or "putter side" of the green in order to have the best chance at getting up and down for par.