wet nurse

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

• noun A woman who suckles another woman's child.
• noun One who treats another with excessive care or solicitude.

from The Century Dictionary.

• noun A woman employed to suckle the infant of another.
• To act as a wet-nurse to; suckle.
• Hence To coddle as a wet-nurse does: treat with the tenderness shown to an infant.

from the GNU version of the Collaborative International Dictionary of English.

• A nurse who suckles a child, especially the child of another woman. Cf. dry nurse.

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

• noun A woman hired to suckle another woman's child.
• noun figuratively, by extension Someone who treats someone else with excessive care.
• verb transitive To act as a wet nurse (in either sense.)

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

• noun a woman hired to suckle a child of someone else
• noun a woman hired to suckle a child of someone else
• verb give suck to
• noun a woman hired to suckle a child of someone else