Short for "Do It Yourself", which is a phrase used when a person makes something themself rather than buying it pre-assembled. Often diyer
s try to do it themselves in an attempt to save money. Many an idiot as made the mistake of trying DIY only to have wasted time and money with no satisfying end result.
Oh no! Dad's going to try to fix the car DIY. Remember the last time he did that? Take cover!