smile

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

• noun A facial expression characterized by an upward curving of the corners of the mouth and indicating pleasure, amusement, or derision.
• intransitive verb To have or form a smile.
• intransitive verb To look with favor or approval.
• intransitive verb To express cheerful acceptance or equanimity.
• intransitive verb To express with a smile.

from The Century Dictionary.

• To show a change of the features such as characterizes the beginning of a laugh; give such an expression to the face: generally as indicative of pleasure or of slight amusement, but sometimes of depreciation, contempt, pity, or hypocritical complaisance.
• To look gay or joyous, or have an appearance such as tends to excite joy; appear propitious or favorable: as, the smiling spring.
• To drink in company.
• To ferment, as beer, etc.
• To express by a smile: as, to smile a welcome; to smile content.
• To change or affect (in a specified way) by smiling: with a modifying word or clause added.
• To smile at; receive with a smile.
• noun An expression of the face like that with which a laugh begins, indicating naturally pleasure, moderate joy, approbation, amusement, or kindliness, but also sometimes amused or supercilious contempt, pity, disdain, hypocritical complaisance, or the like. Compare smirk, simper, and grin.
• noun Gay or joyous appearance; an appearance that would naturally be productive of joy: as, the smiles of spring.
• noun Favor; countenance; propitiousness: as, the smiles of Providence.
• noun A drink, as of spirit, taken in company and when one person treats another; also, the giving of the treat: as, it is my smile.

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

• transitive verb To express by a smile
• transitive verb rare To affect in a certain way with a smile.
• intransitive verb To express amusement, pleasure, moderate joy, or love and kindness, by the features of the face; to laugh silently.
• intransitive verb To express slight contempt by a look implying sarcasm or pity; to sneer.
• intransitive verb To look gay and joyous; to have an appearance suited to excite joy
• intransitive verb To be propitious or favorable; to favor; to countenance; -- often with on.
• noun The act of smiling; a peculiar change or brightening of the face, which expresses pleasure, moderate joy, mirth, approbation, or kindness; -- opposed to frown.
• noun A somewhat similar expression of countenance, indicative of satisfaction combined with malevolent feelings, as contempt, scorn, etc.
• noun Favor; countenance; propitiousness.
• noun Gay or joyous appearance.

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

• noun A facial expression comprised by flexing the muscles of both ends of one's mouth while showing the front teeth, without vocalisation, and in humans is a common involuntary or voluntary expression of happiness, pleasure, amusement or anxiety.
• verb transitive or (intransitive) To have a smile on one's face

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

• verb change one's facial expression by spreading the lips, often to signal pleasure
• verb express with a smile
• noun a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement