noun. Any of several deciduous trees of the genus Malus, native to North America and Eurasia and having clusters of white, pink, or reddish flowers.

noun. The small tart fruit of such a tree, sometimes used to make jelly and preserves.

noun. Any of the wild varieties of apple tree, genus Malus, which generally yield small, bitter fruit (in comparison to domestic apples, Malus domestica.

noun. The fruit of this tree.

noun. An unpleasant person; a person who is crabby.