Soroptimist

1530s, "a society of women, body of women united for some purpose," from Medieval Latin sororitas "sisterhood;" as an adjective, "of or pertaining to sisters," from Latin soror "sister" (see sister). The sense of "women's society in a college or university" is attested by 1887 (Alpha Delta Pi claims founding in 1851).

1759, "one who believes in metaphysical optimism," from French optimiste (1752); see optimism + -ist. Meaning "person of a hopeful disposition" is recorded by 1766.