triple

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

• adjective Consisting of three parts or members.
• adjective Three times as much in size, strength, number, or amount.
• adjective Music Having three beats to a measure.
• noun A number or quantity three times as great as another.
• noun Something having three identifiable or prominent parts or members.
• noun Something capable of carrying or moving three people or things, as a chairlift.
• noun Baseball A hit enabling the batter to reach third base.
• intransitive verb To make three times as great in number or amount.
• intransitive verb To be or become three times as great in number or amount.
• intransitive verb Baseball To make a triple.

from The Century Dictionary.

• noun In geometry: A triad of points.
• noun A triad of systoms of orthogonal surfaces.
• To make threefold or thrice as much or as many; treble.
• To be thrice as great or as many as.
• To alter from single or double to triple action, as a single or double expansion-engine into a triple expansion-engine; fit up with triple expansion-engines, as a vessel which has previously used a single or double expansion-engine.
• To increase threefold.
• Consisting of three; threefold; characterized by a subdivision into three parts or into threes: as, a triple knot; a triple window.
• Three times repeated; treble.
• Being one of three; third.
• A league between France, Great Britain, and the Netherlands, formed in 1717, and directed chiefly against Spain. After the accession to it of Austria in 1718 it was known as the Quadruple Alliance.
• An alliance between Germany, Austria-Hungary, and Italy, formed about 1883, and designed to check Russia and also France. It is chiefly the creation of Prince Bismarck, and by its provisions the three powers are bound to support one another in certain contingencies. Its influence has succeeded to that of the League of the Three Emperors (the German, Austrian, and Russian), which was also largely the creation of Bismarck.
• A bearing representing three royal or imperial crowns set one upon another in pale. Such a bearing, having also clouds at the base, forms part of the arms of the London Drapers' Company.
• noun In music, same as treble.
• noun plural In change-ringing, changes rung on seven bells.

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

• intransitive verb To make threefold, or thrice as much or as many; to treble.
• adjective Consisting of three united; multiplied by three; threefold.
• adjective Three times repeated; treble. See Treble.
• adjective obsolete One of three; third.
• adjective the crown, or tiara, of the pope. See Tiara, 2.
• adjective a compound steam engine in which the same steam performs work in three cylinders successively.
• adjective (Mus.) a measure of tree beats of which first only is accented.
• adjective (Math.) a ratio which is equal to 3.
• adjective (Chem.) a salt containing three distinct basic atoms as radicals; thus, microcosmic salt is a triple salt.
• adjective (Astron.) a system of three stars in close proximity.
• adjective (Mus.) that time in which each measure is divided into three equal parts.
• adjective in an automatic air brake for railroad cars, the valve under each car, by means of which the brake is controlled by a change of pressure in the air pipe leading from the locomotive.

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

• adjective Made up of three related elements, often matching
• adjective Three times the quantity
• adjective Designed for three users
• adjective Folded in three; composed of three layers
• adjective Having three aspects; very ambiguous.
• adjective music Of time, three times as fast as very fast.
• noun informal A drink with three portions of alcohol.
• noun US A hamburger with three patties.
• noun baseball A three-base hit
• noun curling A takeout shot in which three stones are removed from play.
• noun mathematics, computing A sequence of three elements or 3-tuple.
• verb To multiply by three