1. Of a plant, to begin bearing or become full of fruit. The raspberry bushes in our back yard are finally fruiting up.
2. To add fruit to something. In this usage, a noun or pronoun can be used between "fruit" and "up." I've been fruiting up my smoothies with mango and pineapple recently.
3. To mix alcohol with a sweet drink, such as fruit juice or carbonated beverages. In this usage, a noun or pronoun can be used between "fruit" and "up." What's the point of drinking expensive cognac if you're just going to fruit it up?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.