hour·glass 
/ˈawɚˌglæs, Brit ˈawəˌglɑ:s/ noun
plural hour·glass·es /ˈawɚˌglæs, Brit ˈawəˌglɑ:s/ noun [count] : a device for measuring time ◊An hourglass is a glass container with an upper part and a lower part connected by a narrow opening. The upper part contains sand which flows into the lower part in a specified amount of time (such as an hour).
— hourglass adjective always used before a noun
▪ an hourglass shape
▪ an hourglass shape
