Fix up Definition 1 of 3Pro Tip 1/3Visual Improvement Often implies making something old or damaged look better or as good as new. After you fix up that old bike, it will shine again. Pro Tip 2/3Not always professionals The phrase can mean professional repairs, but also DIY improvements by anyone. I will fix up the leaky faucet myself this weekend. Pro Tip 3/3Broader than repair 'Fix up' can also mean to clean or tidy, not just to repair. We need to fix up the room before the guests arrive.