a graduate or former student of a specific school, college, or university.
a former associate, employee, member, or the like: He invited all the alumni of the library staff to the party.
Origin: 1635–45; < Latin: foster son, pupil, equivalent to al- (stem of alere to feed, support) + -u- (< stem-vowel *-o- in interior syllable) + -m(i)nus, orig. passive participial suffix (cf. adult, old), akin to Greek-menos; see phenomenon
Can be confused: alum, alumna, alumnae, alumni, alumnus (see usage note at the current entry).
Usage note Alumnus (in Latin a masculine noun) refers to a male graduate or former student; the plural is alumni. An alumna (in Latin a feminine noun) refers to a female graduate or former student; the plural is alumnae. Traditionally, the masculine plural alumni has been used for groups composed of both sexes and is still widely so used: the alumni of Indiana University. Sometimes, to avoid any suggestion of sexism, both terms are used for mixed groups: the alumni/alumnae of Indiana University or the alumni and alumnae of Indiana University. While not quite equivalent in meaning, the terms graduate and graduates avoid the complexities of the Latin forms and eliminate any need for using a masculine plural form to refer to both sexes.
1640s, from L. "a pupil," lit. "foster son," vestigial present passive participle of alere "to nourish" (see old), with ending akin to Gk. -omenos. Plural is alumni. Fem. is alumna (1882), fem. plural alumnae.