Merriam-Webster Collegiate Dictionary - morgan

 I. noun  Etymology: Justin ~ died 1798 American teacher  Date: 1841 any of an American breed of light strong horses originated in Vermont from the progeny of one prepotent stallion of uncertain ancestry  II. biographical name Daniel 1736-1802 American general in Revolution  III. biographical name Sir Henry 1635-1688 English buccaneer  IV. biographical name John Hunt 1825-1864 American Confederate cavalry officer  V. biographical name J(ohn) P(ierpont) 1837-1913 American financier  VI. biographical name J(ohn) P(ierpont) Jr. 1867-1943 son of J.P. American financier  VII. biographical name Thomas Hunt 1866-1945 American geneticist  VIII. biographical name William Wilson 1906-1994 American astronomer MORGAN  noun  Etymology: Thomas Hunt Morgan  Date: 1919  1. a unit of inferred distance between genes on a chromosome that is used in constructing genetic maps and is equal to the distance for which the frequency of crossing over between specific pairs of genes is 100 percent  2. centi~