| n. | 1. | Two of the same kind; a pair; a couple. |
| 2. | (Print.) A word or words unintentionally doubled or set up a second time. |
| 3. | 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. |
| 4. | (Lapidary Work) 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. |
| 5. | (Opt.) 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. |
| 6. | Two dice, each of which, when thrown, has the same number of spots on the face lying uppermost; as, to throw doublets. |
| 7. | A game somewhat like backgammon. |
| 8. | 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. |