balsam pear

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A tropical, Old World, tendril-bearing annual vine (Momordica charantia) having yellow flowers and orange, warty fruits that open at maturity to expose red-coated seeds.
2. n. The immature fruit of this plant, used as a vegetable in Asian cuisine. The ripe fruit is not eaten. Also called bitter gourd, bitter melon.

Wiktionary

1. n. bitter melon

WordNet 3.0

1. n. tropical Old World vine with yellow-orange fruit