Green’s Dictionary of Slang

1. (US) a foot, thus trilby case, a shoe; note cite 1900 (US) suggests size rather than beauty.

1895		People 7 July in Ware (1909) 250/1: Having exhausted palmistry an American paper has spent its energy of psychological investigation on the foot (I beg pardon, the trilby), but a rival comes out with a page of illustrated description of the mouth.
1896		E.W. Rogers [perf. Vesta Tilley] Only a Pair of Shoes 🎵 Only a pair of shoes / Number twelves with leather laces, just a pair of Trilby cases .
1900		Sydney Sportsman (Surry Hills, NSW) 10 Oct. 1/1: How will Mossy Isaacs perform when he has to shuffle his corn-covered trilbies over the A.J.C. gravel patch.
1900		Nat. Police Gaz. (NY) 21 Apr. 6/1: Trilby Foot Gave Her Away. The extremely large foot of a female burglar [etc].
1902		Truth (Sydney) 6 Apr. 5/4: In another moment she grabbed the ‘trilby case,’ CAUGHT ADA BY THE HAIR, and banged and belted her with the heel end.
1905		Marvel III:60 5: Bring up my boots! Do you tink I’m going to walk all ober de sloshy streets of London wid my bare trilbies.
1906		Sun. Times (Perth) 29 Apr. 4/7: She immediately proceeded to kick holes in another bye-law by placing her trilbies on the opposite cushion.
1909		N.Z. Truth 16 Jan. 6/2: [She] raised her right trilby and kicked him violence on the spine.
1914		Sport (Adelaide) 25 Sept. 5/6: Have you ever heard the story of Jim L’s feet? Steamrollers [...] are never needed when we have Jim L’s trilby’s.
1920		Marvel 21 Aug. 13: Thee won’t like my clogs on thy trilbies!
1947		(con. 1870s) F. Weitenkampf Manhattan Kaleidoscope 83: For a while after the publication of DuMaurier’s Trilby, ladies feet were archly referred to as ‘trilbies.’.

2. (US) a cooked pig’s foot.

1896

Sun (NY) 28 Mar. 2/6: ‘Gimme a Trilby foot’ means ‘Pass me a fried pig’s foot’. The same deasire is expressed in a request for a ‘grunter’ or a ‘squealer’.