mid-13c., from sun, n. + shine, n.. Old English had sunnanscima "sunshine;" while sunscin meant "a mirror, speculum." Meaning "happy person who brightens the lives of others" is from 1942. Sunshine law in reference to U.S. open-meeting legislation is recorded from 1972, from the notion of shining the light of public access on deliberations formerly held behind closed doors. Related: Sunshiny.