Abney level a surveying instrument consisting of a spirit level and a sighting tube; used to measure the angle of inclination of a line from the observer to the target
Aaron Burr United States politician who served as vice president under Jefferson; he mortally wounded his political rival Alexander Hamilton in a duel and fled south (1756-1836)
Abel Tasman Dutch navigator who was the first European to discover Tasmania and New Zealand (1603-1659)
401-k plan a retirement savings plan that is funded by employee contributions and (often) matching contributions from the employer; contributions are made from your salary before taxes and the funds grow tax-free until they are withdrawn, at which point they can be converted into an IRA; funds can be transferred if you change employers and you can (to some extent) manage the investments yourself
Aaron Copland United States composer who developed a distinctly American music (1900-1990)
A. A. Milne English writer of stories for children (1882-1956)
ABO system a classification system for the antigens of human blood
A. E. Housman English poet (1859-1936)
Abies fraseri small fast-growing but short-lived fir of southern Alleghenies similar to balsam fir but with very short leaves
Abies grandis lofty fir of the Pacific coast of northwestern America having long curving branches and deep green leaves
Abies lowiana medium to tall fir of central to western United States having a narrow erect crown and soft wood
Abies venusta a pyramidal fir of southwestern California having spiny pointed leaves and cone scales with long spines
Aare River a river in north central Switzerland that runs northeast into the Rhine
Abies alba tall timber tree of central and southern Europe having a regular crown and grey bark
8 May 1945 the date of Allied victory in Europe, World War II
ADP system a system of one or more computers and associated software with common storage
12-tone system a type of serial music introduced by Arnold Schoenberg
1st class mail that includes letters and postcards and packages sealed against inspection
440 yards a unit of length equal to a quarter of 1 mile
880 yards a unit of length equal to half of 1 mile