emeritus

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Retired but retaining an honorary title corresponding to that held immediately before retirement: a professor emeritus.
2. n. One who is retired but retains an honorary title corresponding to that held immediately before retirement.

Century Dictionary and Cyclopedia

1. Having served out one's time; having done sufficient service; discharged with honor from the performance of public duty on account of infirmity, age, or long service, but retained on the rolls: as, a professor emeritus; a rector emeritus.
2. n. In Roman history, a soldier or public functionary who had served out his time and retired from service. Such servants were entitled to some remuneration answering to modern half pay.
3. n. One who has served out his time or done sufficient service; one who has been honorably discharged from public service or from a public office, as an officer in a university or college, usually with continuance of full or partial emolument.

Wiktionary

1. adj. retired, but retaining an honorific version of previous title; especially used with professor.
2. n. A person retired in this sense (feminine form emerita).

GNU Webster's 1913

1. adj. Honorably discharged from the performance of public duty on account of age, infirmity, or long and faithful services; -- said of an officer of a college or pastor of a church.
2. n. A veteran who has honorably completed his service.

WordNet 3.0

1. n. a professor or minister who is retired from assigned duties
2. adj. honorably retired from assigned duties and retaining your title along with the additional title `emeritus' as in `professor emeritus'