Word Origin & History
O.E. cyse, from W.Gmc. *kasjus, from L. caseus "cheese," from PIE base *kwat- "to ferment, become sour." Earliest refs. would be to compressed curds of milk used as food; pressed or molded cheeses with rinds are 14c. As a photographer's word to make subjects hold a smile, it is attested from 1930, but
in a reminiscence of schoolboy days, which suggests an earlier use. To make cheeses was a schoolgirls' amusement (1835) of wheeling rapidly so one's petticoats blew out in a circle then dropping down so they came to rest inflated and resembling a wheel of cheese; hence, used figuratively for "a deep curtsey."