server

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

• noun One who serves food and drink.
• noun Something, such as a tray, that is used in serving food and drink.
• noun An altar server.
• noun Law One who serves a legal process, such as a summons or court order.
• noun Sports The player who serves, as in court games.
• noun A file server.
• noun A computer that processes requests for HTML and other documents that are components of webpages.

from The Century Dictionary.

• noun A male animal, particularly a bull, that copulates with, or serves, the female.
• noun One who serves.
• noun Specifically
• noun In the Roman Catholic and Anglican churches, an attendant on the priest at a low celebration of the eucharist, who helps the priest to vest and unvest, arranges the service-book, lights and extinguishes the altar-lights, places the elements and cruets on the credence and brings them to the priest at the offertory, brings the priest the basin and towel and pours the water at the lavabo, pours out the ablutions of wine and water, and ministers in other ways. The server is usually a boy or other layman, and represents, as far as a layman can, the priest's assistants and the choir at a high celebration.
• noun One who serves up a meal, or sets the dishes on table.
• noun In the game of tennis or of lawn-tennis, the player who serves or strikes the ball first. See lawn-tennis.
• noun That which serves or is used in serving.

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

• noun One who serves.
• noun A tray for dishes; a salver.

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

• noun One who serves; a waitress or waiter.
• noun A tray for dishes; a salver.
• noun computing A computer or a program which provides services to other programs or users, either in the same computer or over a computer network.

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

• noun utensil used in serving food or drink
• noun (court games) the player who serves to start a point
• noun (computer science) a computer that provides client stations with access to files and printers as shared resources to a computer network
• noun a person whose occupation is to serve at table (as in a restaurant)