coordinate bond

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

• noun A covalent chemical bond between two atoms that is produced when one atom shares a pair of electrons with another atom lacking such a pair.

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

• noun chemistry A type of covalent bond where the two electrons being shared originate from the same atom; a dative bond.
• noun chemistry One of the bonds between the central metal atom of a coordination compound and its ligands.

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

• noun a covalent bond in which both electrons are provided by one of the atoms