pillbox

noun

1. a box, usually shallow and often round, for holding pills.
2. a small, low structure of reinforced concrete, enclosing machine guns, and employed as a minor fortress in warfare.
3. a small, round, brimless hat with straight sides and a flat top, worn especially by women.

noun

1. a box for pills
2. a small enclosed fortified emplacement, usually made of reinforced concrete
3. a small round hat, now worn esp by women

n.also pill-box, “box for holding pills,” 1730, from pill (n.) + box (n.). As a small round concrete machine gun nest, it came into use in World War I. As a type of hat, attested from 1958.