sweet orange

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An orange tree (Citrus sinensis) that is widely cultivated in warm regions and has yellow to orange fruit with sweet juicy pulp.
• noun The fruit of this tree.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A type of citrus fruit, commonly known as the orange. The species name is Citrus sinensis.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun probably native to southern China; widely cultivated as source of table and juice oranges
• noun orange with sweet juicy pulp; often has a thin skin