Definition of doublet

• a. - Two of the same kind; a pair; a couple.
• a. - A word or words unintentionally doubled or set up a second time.
• a. - A close-fitting garment for men, covering the body from the neck to the waist or a little below. It was worn in Western Europe from the 15th to the 17th century.
• a. - A counterfeit gem, composed of two pieces of crystal, with a color them, and thus giving the appearance of a naturally colored gem. Also, a piece of paste or glass covered by a veneer of real stone.
• a. - An arrangement of two lenses for a microscope, designed to correct spherical aberration and chromatic dispersion, thus rendering the image of an object more clear and distinct.
• a. - Two dice, each of which, when thrown, has the same number of spots on the face lying uppermost; as, to throw doublets.
• a. - A game somewhat like backgammon.
• a. - One of two or more words in the same language derived by different courses from the same original from; as, crypt and grot are doublets; also, guard and ward; yard and garden; abridge and abbreviate, etc.