shim

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A thin, often tapered piece of material, such as wood, stone, or metal, used to fill gaps, make something level, or adjust something to fit properly.
2. v. To fill in, level, or adjust by using shims or a shim.

Century Dictionary and Cyclopedia

1. n. A white spot, as a white streak on a horse's face.
2. n. An ignis fatuus.
3. Same as shime.
4. n. Broadly, in machinery, a thin slip (usually of metal, but often of other material) used to fill up space caused by wear, or placed between parts liable to wear, as under the cap of a pillow-block or journal-box. In the latter case, as the journal and box wear and the journal gets loose, the removal of one or more shims allows the cap to be forced down by its tightening bolts and nuts against the journal to tighten the bearing.
5. n. In stone-working and quarrying, a plate used to fill out the space at the side of a jumper-hole, between it and a wedge used for separating a block of stone, or for contracting the space in fitting a lewis into the hole.
6. n. A shim-plow (which see, under plow).
7. To wedge up or fill out to a fair surface by inserting a thin wedge or piece of material.
8. n. An imperfect shingle, thicker at one side than the other; also, an imperfect stave for a bucket.

Wiktionary

1. n. A wedge.
2. n. A thin piece of material, sometimes tapered, used for alignment or support.
3. n. computing A small library that transparently intercepts and modifies calls to an API, usually for compatibility purposes.
4. n. A kind of shallow plow used in tillage to break the ground and clear it of weeds.
5. n. A small metal device used to pick open a lock.
6. v. To fit one or more shims to a piece of machinery
7. v. To adjust something by using shims
8. n. informal, often derogatory a person characterised by both male and female traits, or by ambiguous male-female traits, also called a he-she; transsexual.
9. n. informal, often derogatory hermaphrodite.

GNU Webster's 1913

1. n. A kind of shallow plow used in tillage to break the ground, and clear it of weeds.
2. n. (Mach.) A thin piece of metal placed between two parts to make a fit.

WordNet 3.0

1. n. a thin wedge of material (wood or metal or stone) for driving into crevices