alpha

Từ điển American Heritage Dictionary 4th

al·pha (ălʹfə)n.
1. The first letter of the Greek alphabet. See table at alphabet.
2. The first one; the beginning.
3. Chemistry. The first position from a designated carbon atom in an organic molecule at which an atom or radical may be substituted.
4. Astronomy. The brightest or main star in a constellation.
5. The mathematical estimate of the return on a security when the return on the market as a whole is zero. Alpha is derived from a in the formula R_i = a + bR_m, which measures the return on a security (R_i) for a given return on the market (R_m) where b is beta.adj.
1. Being the highest ranked or most dominant individual of one's sex. Used of social animals:
the alpha female of the wolf pack.
2. Chemistry. Closest to the functional group of atoms in an organic molecule.
3. Alphabetical. [Greek, of Phoenician origin. See ʾlp in Semitic Roots.]