crabapple

(noun) any of numerous varieties of crab apples cultivated for their small acidic (usually bright red) fruit used for preserves or as ornamentals for their blossoms. Synonyms: crab apple, cultivated crab apple.

(noun) any of numerous wild apple trees usually with small acidic fruit. Synonyms: wild apple, crab apple.

(noun) small sour apple; suitable for preserving. Synonyms: crab apple. Example: "Crabapples make a tangy jelly."