(often in the plural) In general, a product of plant growth useful to man or animals.

Specifically, a sweet, edible part of a plant that resembles seed-bearing fruit (see next sense), even if it does not develop from a floral ovary; also used in a technically imprecise sense for some sweet or sweetish vegetables, such as the petioles of rhubarb, that resemble a true fruit or are used in cookery as if they were a fruit.

A product of fertilization in a plant, specifically:

To produce fruit, seeds, or spores.