opera hat

American  

noun

1. a man's tall, collapsible top hat, held open or in shape by springs and usually covered with a black, silky fabric.

---

opera hat British  

noun

1. Also called: gibus.  a collapsible top hat operated by a spring

---

Etymology

Origin of opera hat

First recorded in 1800–10

Example Sentences

Indeed, two collapsible, black opera hats were kept in the Commons chamber at all times for this very purpose.

From BBC

GIBUS: A man’s collapsible top hat, also called an opera hat.

From Washington Times

GIBUS: A man's collapsible top hat, also called an opera hat.

From US News

Until 1998, MPs were able to wear an "opera hat" to draw attention to themselves to raise a point of order.

From BBC

Shirt, collar, trousers, waistcoat, swallowtail, opera hat, tie, gloves, studs, buttons—everything just his size.

From Project Gutenberg