trilby
Synonym discussion
Sense: noun/1
Trilby, fedora, homburg, and bowler are all classic men's felt hats, but they differ in shape and formality. A trilby has a narrow brim that turns up sharply at the back and a single lengthwise dent running through the crown — it is the most casual of the four and is often associated with jazz musicians and artists. A fedora has a wider brim that can be snapped down or up and a pinched crown rather than a single dent; it is smarter than a trilby but still versatile. A homburg is dressier still, with a stiff curled brim and a single centre dent, traditionally worn with formal business attire. A bowler (or derby) has a hard, rounded crown and a narrow curled brim — it was once everyday city wear but now reads as formal or old-fashioned. To sum up: a trilby says 'relaxed and stylish'; a fedora says 'smart but approachable'; a homburg says 'serious business'; a bowler says 'city gent or vintage flair.' If you see a soft hat with a noticeably narrow, upturned brim and a crease running front to back, that is a trilby.
Etymology
The trilby hat takes its name from the 1895 London stage adaptation of George du Maurier's novel Trilby. In the play, a character wore a hat with a narrow brim and a dented crown — a style that soon caught on with the public. The hat itself had existed before, but the play's huge popularity fixed the name 'trilby' to this particular shape, and it has stuck ever since.
First known use
1897
1897, in the meaning defined above