1) Hat 
• Alt. of Billycock hat
Bil'ly·cock noun , or Bil'ly*cock hat` [ Perh. from bully + cock ; that is, cocked like the hats of the bullies.] A round, low-crowned felt hat; a wideawake. 'The undignified billycocks and pantaloons of the West.' B. H. Chamberlain. « Little acquiesced...
Billycock is the name given to several round-crowned brimmed hats made of felt. They are named after William Coke who had them made for him during the 19th century.
a derby or a hat resembling it. Also called