parent

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

• noun A female person whose egg unites with a sperm or a male person whose sperm unites with an egg, resulting in the conception of a child or the birth of a child.
• noun A female person who is pregnant with or gives birth to a child except when someone else has legal rights to the child.
• noun A person who adopts a child.
• noun A person who raises a child.
• noun An ancestor; a progenitor.
• noun An organism that produces or generates offspring.
• noun A guardian; a protector.
• noun A parent company.
• noun A source or cause; an origin.
• intransitive verb To act as a parent to; raise and nurture.
• intransitive verb To cause to come into existence; originate.
• intransitive verb To act as a parent.

from The Century Dictionary.

• noun A father or mother; one who has generated or produced: correlated to child, offspring, descendant.
• noun By extension, any animal in relation to its offspring, or a plant in relation to other plants produced from it; any organism in relation to the individual organisms which it produces by any process of reproduction.
• noun One who or that which produces; an author; a cause; a source.
• noun A kinsman; relative.
• Serving as or pertaining to a parent or source.

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

• noun One who begets, or brings forth, offspring; a father or a mother.
• noun That which produces; cause; source; author; begetter.
• noun (Biol.) See Mother cell, under Mother, also Cytula.
• noun (Biol.) a nucleus which, in cell division, divides, and gives rise to two or more daughter nuclei. See Karyokinesis, and Cell division, under Division.

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

• noun A person who acts as a parent in rearing a child; a step-parent or adoptive parent.
• verb To act as parent, to raise or rear.

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

• verb bring up
• noun a father or mother; one who begets or one who gives birth to or nurtures and raises a child; a relative who plays the role of guardian
• noun an organism (plant or animal) from which younger ones are obtained