merger

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or an instance of merging; union.
2. n. The union of two or more commercial interests or corporations.
3. n. Law The absorption of a lesser estate, liability, right, action, or offense into a greater one.

Century Dictionary and Cyclopedia

1. n. One who or that which merges.
2. n. In the law of conveyancing, the sinking or obliteration of a lesser estate in lands, etc., resulting when it is transferred without qualification to the owner of a greater estate in the same property (or the like transfer of the greater estate to the owner of the lesser), if there be no intermediate estate. At common law the lesser estate was not deemed to be added to the greater, but to be extinguished, so as to free the greater estate from the qualification or impairment which the existence of the lesser estate had constituted. Thus. if an owner of the fee of land on which there was an outstanding lease, owned by another person, acquired the lease, the lease was thereby annulled, and he thereafter held simply as owner of the fee. It resulted sometimes that, if his title to the fee proved defective, he could not avail himself of any claim under the lease.
3. n. In the law of contracts, the extinguishment of a security for a debt by the creditor's acceptance of a higher security, such as a bond in lieu of a note, or a judgment in lieu of either: so called because such acceptance, by operation of law, and without intention of the parties, merges the lower security.
4. n. A merging of the interests and control of two or more corporations, engaged in the same line, or in allied lines, of business, into a single corporation which exchanges its stock for that of the merging corporations, which however preserve, nominally at least, their separate identity.

Wiktionary

1. n. The act or process of merging two or more parts into a single unit.
2. n. economics The legal union of two or more corporations into a single entity, typically assets and liabilities being assumed by the buying party.
3. n. law An absorption of one or more estate(s) or contract(s) into one other, all being held by the same owner; of several counts of accusation into one judgement, etc.
4. n. linguistics A type of sound change where two or more sounds merge into one.

GNU Webster's 1913

1. n. One who, or that which, merges.
2. n. (Law) An absorption of one estate, or one contract, in another, or of a minor offense in a greater.
3. n. The combining of two groups into a unified single group under a single leadership, with voluntary participation by the leaders or management of both groups.
4. n. (Business, Finance) The combining of two commercial enterprises into a unified single enterprise under a single management, with voluntary participation by both parties. Compare acquisition and takeover.

WordNet 3.0

1. n. the combination of two or more commercial companies
2. n. an occurrence that involves the production of a union