alpha

(noun) the 1st letter of the Greek alphabet.

(noun) the beginning of a series or sequence. Example: "The alpha and omega, the first and the last, the beginning and the end"--revelations."

(adj) first in order of importance. Examples: "The alpha male in the group of chimpanzees." "The alpha star in a constellation is the brightest or main star."

(adj) early testing stage of a software or hardware product. Example: "Alpha version."